The atypicality of sustainable luxury products

Correspondence Carmela Donato, Department of Business and Management, LUISS University, Viale Romania, 32 – 00197 Rome, Italy. Email: donatoc@luiss.it Abstract This study tackles the issue of how consumers might perceive luxury products' sustainability‐focused communication. We compare consumers' reactions when luxury brands communicate their focus on either product sustainability or product excellence (i.e., a sustainability‐ vs. excellence‐focused communication strategy, respectively). We predict that consumers perceive the former as more atypical for a luxury brand, which renders the communication more effective at enhancing consumers' willingness to buy the brand's products. Across six experiments, we demonstrate that perceived atypicality mediates the effect of luxury product communication strategy on consumers' willingness to buy; that perceived atypicality increases willingness to buy by increasing consumers' perception about the uniqueness of the communication strategy; that the effect of perceived atypicality is stronger for consumers with a higher chronic need for uniqueness; and that the greater effectiveness of a sustainability‐focused communication strategy on atypicality and willingness to buy is peculiar to luxury products (i.e., it does not manifest for mass‐market products). From a managerial perspective, our findings demonstrate that luxury brands may innovate their communication strategies by leveraging sustainability rather than product excellence.

While the negative view has been prevalent, the significant decline in articles about it suggests that scholars have started to see the perspective as inadequate. Indeed, luxury consumers are increasingly aware of sustainability issues. In particular, younger affluent generations have higher expectations that luxury brands align with values such as preserving the environment and the welfare of individuals and communities involved in the luxury business. 1 The present research focuses on consumers' reactions to luxury brands' communication messages that highlight whether a given product is manufactured in an environmentally manner (i.e., using sustainable resources and processes). Luxury companies have been devoting a great deal of attention to the impact of their activities on the environment and society (e.g., Deloitte, 2019), frequently highlighting sustainability as a core pillar of their mission and corporate strategy in their official communication channels. However, they seem to be much more reluctant to incorporate sustainability themes into their product-oriented communication, instead emphasizing prestige, quality and performance (in sum, excellence). Gucci, for instance, is renowned for having developed the Environmental Profit & Loss (EP&L): a worldwide, eco-friendly program aimed at reducing the environmental impact of its activities through, for example, increased attention to the use and management of chemicals, the development of innovative, eco-friendly materials, and the sustainable sourcing and traceability of raw materials. Nonetheless, a review of the company's website indicates that only one of about 80 female and male product categories lists sustainability as a product feature.
In contrast to this practice, we propose that focusing luxury product communication on sustainability features might enhance consumers' willingness to buy (hereafter, WTB) luxury products compared to a more traditional communication focus on luxury product excellence. Theoretically, we propose that one possible mechanism through which sustainability-focused communication positively affects WTB is the following: buying a sustainable luxury product elicits consumers' feelings of uniqueness, defined as the "feelings of being unique, special, and separable from the majority" (Jebarajakirthy & Das, 2021, p. 60). Importantly, we argue that such feelings of uniqueness associated with owning a sustainable luxury product are driven by consumers' perception that a product communication focused mainly on sustainability is still seen as atypical for promoting a luxury product (which is typically promoted through an excellence-focused communication). Atypicality can be defined as the perception that something deviates significantly from what is typical, common, expected, and taken for granted (Schnurr, 2017).
To summarize, we hypothesize the existence of a serial mediation process whereby promoting a luxury product through a focus on sustainable manufacturing (rather than on product excellence) is seen by consumers as atypical for a luxury product, and this atypicality elicits feelings of uniqueness associated with the idea of owning that product, which ultimately drives WTB. Table 1 defines the key constructs investigated in the present research.
Importantly, we highlight that the mechanism hypothesized in this study applies to the luxury context only. Indeed, building on the idea that consumers of special-occasion products look for exclusivity, Pocheptsova et al. (2010Pocheptsova et al. ( , p. 1059) stated that "for special-occasion products, an inference that the product is exclusive, unusual, unique, out of the ordinary, or distinctive is associated with positive value," while the same does not apply to ordinary products.

| Sustainable luxury consumption
Given consumers' increasing concern for the environmental and societal impact of their consumption choices, most luxury brands have come to realize they can no longer ignore the topic, as they have traditionally done (Athwal et al., 2019). Luxury consumers increasingly want "convincing answers to questions of environmental and social responsibility" (Bendell & Kleanthous, 2007, p. 8), which may be the result of a larger trend from the last two decades: namely, the accessibility of luxury goods for the "happy many" rather than the "privileged few" (Dubois & Laurent, 1996;Moraes et al., 2017). In line with companies and consumers' growing interest in sustainability issues, scholarly research has been engaging in a very lively debate on sustainable luxury branding and consumption. Table 2 summarizes the main authors, perspectives and research focuses emerging from an analysis of the relevant literature on sustainable luxury. This analysis underscores the emergence of a positive view of sustainable luxury among relatively recent scholarship. In essence, this view advocates that sustainability elements can bring benefits to luxury products and brands in terms of consumer assessment and purchase intentions. The compatibility between luxury and sustainability might be explained by the fact that "both focus on rarity" (Kapferer, 2010, p. 41). As stated by Amatulli et al. (2017Amatulli et al. ( , 2018, "luxury is about high-quality products that are objectively rare because they employ rare materials and unique craftsmanship skills" and "sustainable development is about preserving natural resources by limiting the excessive use of materials that can exceed the world's recycling capabilities." Heil and Langer (2017), moreover, built on the "fallacy of clean luxury" (Davies et al., 2012)-which contends that high-price products are automatically more ethical than cheaper products since they abide by higher quality standards and symbolize prestige-to argue that luxury brands should be considered as more sustainable than ordinary brands. The convergence between luxury and sustainability, under certain 1 https://luxe.digital/business/digital-luxury-trends/millennials-buy-sustainable-luxury/ conditions, has also been supported by empirical studies. Among the studies on luxury product characteristics, Janssen et al. (2014), for instance, demonstrated that, for enduring luxury product categories (e.g., jewelry), a scarce product is perceived as more socially responsible than a more widely available product, leading to positive product attitudes; however, this effect does not occur for ephemeral luxury product categories (e.g., clothing). De Angelis et al. (2017), moreover, demonstrated that luxury brands can be both "gold and green" , p. 1516: They showed that consumers develop more positive attitudes toward luxury companies' new green products when their designs are similar to models produced by green, non-luxury companies rather than the luxury company's previous non-green products. Chang et al. (2019) showed that high-power individuals evaluate a luxury brand's CSR campaign more positively than low-power individuals and Pantano and Stylos (2020) highlighted that renting luxury appaeral-a more sustainable form of consumption compared to purchasing-can increase consumers willingness to show their social status, which aligns with the general idea that luxury consumers are particularly concerned about promoting their image (e.g., Fazeli et al., 2020).
Other studies have examined the effect of luxury companies' sustainability-oriented communication strategies. Nash et al. (2016) found that environmental messages do not diminish the perceived value of luxury jewels. Moreover, Amatulli et al. (2018) demonstrated that external CSR activities (i.e., those related to the legal and philanthropic CSR dimensions; see, for instance, Carroll, 1979) lead to an increase in WTB and consumer attitudes toward luxury goods compared to internal CSR activities (i.e., those related to the economic and ethical CSR dimensions; see, for instance, Carroll, 1979), especially when consumers have a higher status and conspicuous consumption orientation. In a very recent study on luxury hotels' communication strategies, Amatulli, De Angelis, and Stoppani (2020) found that communication highlighting a hotel's attention to environmental sustainability increases consumers' willingness to book a room compared to communication highlighting a hotel's attention to customer service-the former increasing the hotel's perceived integrity. Finally, in an investigation of unsustainable luxury (i.e., luxury goods that satisfy consumers' need for exclusiveness and personal pleasure, but do not meet sustainability principles), Amatulli, De Angelis, Pino, et al. (2020) showed that consumers may feel more guilty upon discovering that a purchased luxury product is unsustainable compared to a mass-market product. This effect stems from their higher expectations about luxury products' sustainability.
Clearly, there is a sharp contrast between the positive view (embodied in this relatively recent stream of studies) of sustainable luxury and the negative view that suffuses most of the initial studies, which essentially treated luxury and sustainability as conflicting concepts (Achabou & Dekhili, 2013;Beckham & Voyer, 2014;Davies et al., 2012;Griskevicius et al., 2010;Kapferer & Michaut, 2014;Torelli et al., 2012).
The negative view of sustainable luxury consumption builds off "the simplistic clichéthat luxury is mainly associated with excess, personal pleasure, superficiality, ostentation, high quality, conspicuousness and resistance to external normative influence," while "sustainability is about altruism, sobriety, moderation, ethics and adaptation to social norms" (Amatulli, De Angelis, Pino, et al., 2020, p. 823). Indeed, empirical findings have demonstrated that luxury consumers tend to regard sustainability elements as factors of secondary importance in their purchasing decisions (Davies et al., 2012;Griskevicius et al., 2010). Sometimes, sustainability elements seem to even undermine luxury consumers' perceptions of goods' overall quality (Achabou & Dekhili, 2013). To illustrate, Davies et al. (2012) demonstrated that luxury consumers might prefer to buy an unsustainable luxury good over a sustainable one if they believe the former grants higher status and prestige. Achabou and Dekhili (2013), moreover, found that incorporating recycled materials into luxury goods may negatively affect consumer preferences.
In sum, the literature on sustainable luxury consumption outlines two views: the positive, which suggests that consumers might sometimes develop positive attitudes toward and WTB sustainable luxury goods, and the negative, which suggests that consumers are skeptical about sustainable luxury goods because of the perceived incompatibility between sustainability and luxury. However, more recent work has not found evidence to support the negative view. On this basis, we propose that consumers' propensity to buy a luxury product can be higher when such a product is promoted as sustainable rather than merely excellent. We argue that this effect stems from consumers perceiving a communication focus on sustainability as more atypical for a luxury product, with perceived atypicality triggers feelings of uniqueness. In this way, we extend the positive view of sustainable luxury consumption by offering and testing a novel theoretical explanation for it.

| Atypicality in sustainable luxury
Typicality can be defined as the degree to which something aligns with consumers' expectations (Noseworthy et al., 2011). Typical T A B L E 1 Definitions of key constructs investigated in this study

Construct Definition
Sustainable luxury consumption One's ability to consume luxury goods and services that fulfill a person's fundamental needs and improve his or her quality of life without adversely affecting the needs of future generations (Batat, 2020) T A B L E 2 Main authors, perspectives and research focuses on sustainable luxury research (in chronological order) Author items are perceived as representative of a category (Loken & Ward, 1990;Veryzer & Hutchinson, 1998) because they have a good perceived fit with other typical instances of that category. Atypicality, by contrast, is the perception that something deviates significantly from what is typical, common, expected, and taken for granted (Schnurr, 2017). To illustrate, a strategy pursued by a brand can be considered atypical if it is significantly different from the strategies normally pursued by other brands operating in the same business.
Previous consumer behavior research has studied atypicality in the context of brand and product management. In the domain of brand management, the literature has long studied how to manage brand extension strategies (i.e., those strategies through which a brand starts to operate in one or more new product categories outside of its original product category). Scholars have advanced the idea that the success of a brand's extension depends on the extent to which consumers perceive a fit between the brand and the new product category (Aaker & Keller, 1990). However, this fit perception is not limited to concrete attributes, but can instead encompasses the more abstract levels of brand personality and image. For this reason, atypicality has been defined as the extent to which a brand possesses associations and imagery that are broad and abstract rather than closely tied to its original product category (Aaker & Keller, 1990;Batra et al., 2010). On this basis, researchers have found that higher atypicality allows brands to be more "extendable" to different product categories (Batra et al., 2010). In the domain of product management, academic research suggests that, in some circumstances, atypicality may increase product preference (van Ooijen et al., 2016). Indeed, products seen as atypical are more likely to draw attention (Engel et al., 1995). Consumers also tend to associate atypical products with exclusiveness, expensiveness, and therefore with high quality (Creusen & Schoorma, 2005). Interestingly, Loken and Ward (1990, p. 114) noted that consumers "may remember more about a product either because it is typical (and encountered frequently) or because it is atypical and therefore attention getting, perhaps because of its salience relative to other products." In this vein, the product management literature has investigated atypicality in the form of peculiar packaging and design elements. For instance, scholars have demonstrated that products might be perceived as atypical-and therefore visually innovative-when the design deviates from the visual codes typical of the product's category (Landwehr et al., 2013;Talke et al., 2009). In the domain of product design, Brunner et al. (2016) found that the use of symbolic (vs. functional) product design enhances consumers' perceptions about the brand's symbolic nature, especially when the symbolic design is atypical of (or incongruent with) the product category. Moreover, an atypical product design (i.e., a type of design i.e., not representative of the product category; Veryzer & Hutchinson, 1998) renders the brand more exciting because it increases consumers' perception that the product is more interesting; on the other hand, an atypical product design might also lead consumers to question the product's functionality and therefore its reliability (Schnurr, 2017).
That said, previous studies on atypicality focused on product and brand management have neglected to investigate the role that this construct may play in the context of luxury products. We fill this gap by advancing the idea that consumers perceive a luxury product's communication as atypical when it focuses mainly on sustainability.
This argument relies on the idea that luxury brands typically focus their communication messages on themes such as high quality, performance, and prestige, which signal the excellence of the product (Dubois & Duquesne, 1993;Kapferer, 1998;Vigneron & Johnson, 2004). In other words, by adopting a sustainability-focused communication approach, luxury brands might be seen as deviating from the communication focus that consumers would consider typical of a luxury brand. Importantly, previous research has demonstrated that when atypical events happen, they foster a distinctive identity (Goldberg et al., 2016) and are perceived as extraordinary and unique (Reich et al., 2017) because they are seen as unlikely to happen (Sanford & Moxey, 2003;Teigen et al., 2013). Notably, the marketing literature has investigated consumers' preference for uniqueness, showing that consumers feel greater happiness when engaging in uncommon rather than common experiences (Bhattacharjee & Mogilner, 2013). To illustrate, Tian et al. (2001, p. 50) have argued that "products and their uses or displays that become classified as being outside of the norm may serve as recognizable symbols of uniqueness or specialness," and this increases consumers' satisfaction by alleviating the threat to their identity (Snyder & Fromkin, 1977). Moreover, in their study on consumer reactions to companies' mass customization strategies, Franke and Schreier (2008) demonstrated that the perceived uniqueness of a self-designed product increases the perceived product utility beyond the product's esthetic and functional fit.
Notably, there is some evidence that these positive consumers' reactions to product extraordinariness and uniqueness also occur for luxury goods. Specifically, Pocheptsova et al. (2010) investigated the effect of metacognitive difficulty in processing product-related information on consumers' evaluations. The authors found that a perception of product unfamiliarity and unusualness (i.e., metacognitive difficulty) triggers a decrease in product liking for ordinary products, but improves liking toward special-occasion products (i.e., luxury products), due to signaling product exclusivity. Thus, our study builds on the following three ideas: (1) focusing mainly on sustainability in luxury product promotions might be seen as atypical for luxury brands; (2) consumers might appreciate atypical and uncommon experiences associated with luxury products (Pocheptsova et al., 2010) as they signal uniqueness, and (3) uniqueness is widely considered a strong driver of luxury purchasing decisions (Dubois & Duquesne, 1993;Kapferer, 1998;Nueno & Quelch, 1998).
On the basis of previous literature, we reason that sustainabilityfocused luxury product communication might increase consumers' WTB more than excellence-focused luxury product communication.
This effect is explained by the greater perceived atypicality of a sustainability-focused communication compared to an excellencefocused communication, which triggers feelings of uniqueness. In concrete terms, we investigate consumers' responses after being exposed to communication messages portraying luxury products as focused on either environmental sustainability or excellence. From AMATULLI ET AL.
this, we predict the existence of a serial mediation linking luxury product communication focus, perceived atypicality, feelings of uniqueness and WTB. Formally: H1a: A luxury product's sustainability-focused communication will lead to a higher WTB than a luxury product's excellence-focused communication due to a greater perception of atypicality.
H1b: The greater perceived atypicality associated with a luxury product's sustainability-focused communication will lead to higher WTB than a luxury product's excellence-focused communication due to an increase in consumers' feelings of uniqueness.
Notably, we investigate perceived atypicality as not only a feeling stemming from a sustainability-focused luxury product communication, but also as an individual-level trait: that is, as consumers' dispositional NFU. According to Tian et al. (2001, p. 52), consumers' NFU is "the trait of pursuing differentness relative to others through the acquisition, utilization, and disposition of consumer goods for the purpose of developing and enhancing one's self-image and social image." Individuals typically manifest varying degrees of uniqueness motivation (Snyder & Fromkin, 1977). Indeed, NFU has been shown to be positively correlated with individuals' tendency to pursue innovative consumption (Lynn & Harris, 1997a, 1997b. To illustrate, consumers high in NFU tend to look for products they perceive to be unique (Simonson & Nowlis, 2000), for products with distinct designs (Bloch, 1995), and for products that other consumers are not likely to buy (Worchel et al., 1975). Moreover, such consumers are not willing to engage in positive word-of-mouth for the publicly consumed goods that they possess (Cheema & Kaikati, 2010). Furthermore, in their study on fashion trends, Thompson and Haytko (1997) found that some consumers seek to stay ahead in this realm by continuously seeking emerging innovations as a way to resist conformity.
Importantly, Jebarajakirthy and Das (2021) highlighted that NFU dimensions-namely, creative choice counter-conformity, unpopular choice counter-conformity and avoidance of similarity-drive luxury consumption intention. In sum, NFU typically reflects differences among consumers in their counter-conformity motivation, which is "a motivation for differentiating the self via consumer goods" (Tian et al., 2001, p. 52).
We build on this evidence to argue that differences in consumers' NFU will affect their WTB goods from a luxury brand highlighting that its products are sustainable (rather than excellent).
In other words, we predict that atypicality perceptions stemming from a luxury product's sustainability-focused communication will have a stronger (weaker) effect on WTB for consumers with a relatively higher (lower) NFU. Formally, we hypothesize that: H2: The effect of the perceived atypicality of a luxury product's sustainability-focused communication on WTB will be stronger for consumers characterized by a higher versus lower NFU.
To better substantiate our idea about the perceived atypicality of sustainability-focused luxury communication and its positive effect on consumers' WTB, we need to assess whether such a hypothesized atypicality is specific to luxury products. Thus, we further investigate whether the effect hypothesized in H1a is more likely to happen for luxury products than for non-luxury (i.e., mass-market) products. We predict that this might be the case, on the basis that consumers might see massmarket brands as more typically focused on sustainability initiatives (and their communication) than luxury brands.
Indeed, as underlined by Kapferer and Michaut (2015), consumers are particularly interested in sustainability when they perceive that their choice has an immediate impact (Jones, 1991)-and this happens more for consumer products, characterized by highly repeated purchases, than for luxury goods that are purchased less frequently (Davies et al., 2012).
Moreover, consumers favor higher transparency about companies' supply chain disclosures, which is more common among luxury brands than mass-market brands (Jestratijevic et al., 2020). Other studies, conducted on the digital context of social media, have found that luxury fashion brands are less communicative with consumers about their sustainable activities than mass fashion brands (Lee et al., 2018). This is due to several interrelated facts: that mass-market companies typically face higher competition in their sectors compared to luxury companies; that mass-market consumers, more so than luxury consumers, tend to consider different choice options as functional substitutes; and relatedly, that mass-market products and brands lean on sustainability as an important source of competitive advantage (Lowitt, 2011). Consistent with these arguments, luxury brands very rarely make sustainability the core theme of their commercial communications and usually prefer other appeals (e.g., prestige, high quality, status, and style) that signal the excellence of their products. Based on this reasoning, we formally hypothesize: H3: A sustainability-focused product communication has a greater effect on the perceived product atypicality, and in turn on WTB, than an excellence-focused product communication when the product is a luxury one, but not when it is a mass-market one.

| OVERVIEW OF STUDIES
We conducted six studies to test our hypotheses. In the first three stu- For each study, we used different procedures to ensure the recruitment of real luxury consumers. In particular, for Studies 1a-c, we asked participants about their frequency of luxury purchases and excluded those who had never bought a luxury item. In Study 2, we asked participants to indicate the luxury brands that they bought in the last two months and excluded subjects who did not indicate any luxury purchase.
In Study 3, we directly asked the online platform (i.e., Prolific) to only distribute the study to subjects who declared in their profile registration that they bought luxury and fashion items. Finally, in Study 4, we adopted a snowball sampling aimed at only selecting participants who were experienced buyers of luxury fashion items. leather, gold-toned interlocking G on a silver metal base, retrodesign from the 1970s, eight card slots, Made in Italy); the description was slightly adapted for the product excellence condition. In the product sustainability condition, respondents saw the same wallet picture from Gucci's website, but the production description was drawn (and adapted) from the website of Watson and Wolfe, a UK producer of luxury wallets (credit card cases and travel accessories) that is renowned for its commitment to luxury eco-fashion.
To ensure the recruitment of real luxury consumers, we collected data in a private European university, populated by wealthy students who were either used to wearing luxury fashion goods and accessories or had the purchasing power to buy such items. Moreover, we asked respondents with what frequency they buy luxury goods and accessories on a five-point scale (1 = Never, 2 = Rarely, 3 = Sometimes, 4 = Often, 5 = Always). Participants who indicated that they never buy luxury goods were excluded from the analysis. After being exposed to the manipulation, respondents were asked to judge the atypicality of the Gucci wallet using a seven-point, three-item atypicality semantic differential scale (Batra et al., 2010; α = .91), as well as their WTB said wallet (Dodds et al., 1991;α = .92).
Then, as a check of our manipulation, we asked respondents to what extent they thought the promotional message they saw was oriented toward the product's quality or its environmental sustainability Finally, respondents answered demographic questions and were thanked for their participation.

| Results and discussion
We first checked how many respondents indicated that they never bought luxury products (i.e., those who answered "1" on our luxury buying frequency scale), which totaled 119. After excluding these respondents and two who did not answer that question, we retained a total sample of 115 real consumers of luxury goods and accessories

| Method
Since the scenarios used in Study 1a were directly inspired from real brand web-pages (i.e., Gucci for excellence-focused communication and Watson and Wolfe for sustainability-focused communication), their content differ not only in terms of excellence and sustainability, AMATULLI ET AL.
| 7 but also in terms of innovativeness. Moreover, in Study 1a, the mediator variable (i.e., atypicality) was measured before the dependent variable (i.e., WTB), which risks generating a demand effect. To overcome these potential limitations, we conducted Study 1b with the objective of offering robust support to H1a. We used the online platform Prolific to recruit 150 respondents (M age = 26.71, SD = 9.77, 80 females) who were randomly assigned to one of the same two scenarios used in Study 1a, while excluding any reference to innovativeness (see Appendix B). As in Study 1a, we ensured the recruitment of real luxury buyers by asking respondents about their frequency in buying luxury goods and accessories on a five-point scale (1 = Never, 2 = Rarely, 3 = Sometimes, 4 = Often, 5 = Always).
Participants who indicated that they never buy luxury goods were excluded from our analysis. After being exposed to the manipulation, respondents were asked about the perceived atypicality of the Gucci wallet using the same seven-point, three-item measure from Study 1a (α = .88), as well as their WTB the Gucci wallet (Dodds et al., 1991;α = .90

| Results and discussion
After excluding respondents who indicated that they never bought a luxury product, we retained a total sample of 108 real consumers of Then, to test H1a, we used Model 4 of PROCESS, using the same variables as in Study 1a, but controlling for environmental concern (as it varied significantly between the two conditions). The results showed that the luxury product's sustainability-focused communication led to a higher perception of atypicality than the excellence- 6 | STUDY 1C

| Method
In both Studies 1a and 1b, excellence was juxtaposed against sustainability in luxury product communication, which produced evidence that sustainability-focused communication generates a higher WTB compared to excellence-focused communication.
However, one could reasonably argue that these two strategies are not mutually exclusive and that a luxury product can be presented as both sustainable and high-quality. Therefore, we conducted an additional experimental study: a 2 (sustainability-  (4) neither sustainable nor excellent (i.e., we only showed participants a picture of the wallet; see Appendix C). After being exposed to the manipulation, respondents were asked to judge the atypicality of the Gucci wallet (Batra et al., 2010;α = .85) and indicate their WTB the item (Dodds et al., 1991;α = .94).
Then, as a check of our manipulation, we asked respondents to what extent they thought the promotional message they saw was oriented toward the product's quality or its environmental sustainability (1= product quality, 7 = product environmental sustainability). Finally, we asked respondents with what frequency they buy luxury goods and accessories on a five-point scale (1 = Never, 2 = Rarely, 3 = Sometimes, 4 = often, 5 = Always) along with some demographic questions. Aquarian, which was described as an international luxury brand selling status-signaling and high-quality fashion accessories.
Specifically, respondents in the sustainability-focused communication condition were asked to read a (fictitious) excerpt from the "Online Business Magazine" article entitled: "A Luxury Brand and Its Main Strategy: Sustainability," while those in the excellence-focused communication condition were asked to read a (fictitious) excerpt of an article from the same online magazine entitled: "A Luxury Brand and Its Main Strategy: Performance." The article reported either that Aquarian's products are made through "lowly polluting production processes" or made with "high-quality raw materials" (see Appendix D). After being exposed to the manipulation, respondents were asked to indicate how they judged the strategy adopted by Aquarian (as described in the article excerpt) using the same atypicality threeitem scale used in Study 1 (α = .89). Next, respondents rated the uniqueness of the strategy adopted by Aquarian using a three-item, (1 = Not at all; 7 = Very much). Then, to ensure the recruitment of real luxury consumers, we asked participants to explicitly mention at least two luxury brands they had bought from in the last two months. This question served as a check on their status as luxury consumers and was intended to verify whether there were respondents indicating they did not buy at least two luxury brands, in which case they would have been excluded from our analysis. We chose two purchases to verify that participants were dedicated luxury consumers. Finally, participants answered demographic questions.

| Results and discussion
We excluded 37 respondents either because they reported to be underage (less than 18 years old) or because they did not mention any luxury brand whose products they had bought in the last two months. Therefore, we retained a total sample of 308 luxury goods' consumers (M age = 32.75, SD = 12.94, 207 females).
The results of one-way ANOVAs revealed that respondents F I G U R E 2 Results of Study 2 8 | STUDY 3

| Method
The objective of this study was to offer convergence on our idea that uniqueness is one mechanism behind why atypicality drives consumers to report higher WTB toward luxury products whose communication emphasizes sustainability versus excellence. Two hundred and nine respondents (M age = 36.29, SD = 11.45, 127 females), recruited online via Prolific, were randomly assigned to one of the same two descriptions of the fictitious luxury brand Aquarian used in our previous studies (i.e., the description highlighting the brand's focus on sustainability vs. excellence). To ensure the recruitment of real luxury consumers, we directly asked the online platform to only distribute the study to subjects who declared in their profile that they bought luxury and fashion items. Before being exposed to the manipulation, respondents were asked to complete a 12-item NFU scale drawn from Ruvio et al. (2008;α = .93). Next, respondents were asked to rate the perceived atypicality of the strategy adopted by Aquarian using the same three-item scale used in our previous studies (α = .91), as well as their WTB a product from that brand using the same three-item scale from our previous studies (α = .93). Finally, respondents answered demographic questions and were compensated for their participation. t(204) = 3.50, p < .001, see Figure 3).

| Results and discussion
In the next step, we closely examined this interaction by analyzing the conditional indirect effects. We found that this outcome was stronger for respondents with a high NFU level (b = .67, 95% CI: .34, 1.00) compared to those with a medium (b = .53, 95% CI: .26, .83) and low (b = .33, 95% CI: .12, .62) NFU level. Furthermore, since NFU is a continuous variable, we explored the atypicality x NFU interaction through the Johnson-Neyman "floodlight" approach (Spiller et al., 2013). The results of this analysis showed that the coefficient of the effect of atypicality on WTB increased as NFU levels increased (see Appendix C). More importantly, the results revealed the existence of a significant index of moderated mediation (b = .11, 95% CI: .04, .19), which indicates that the full moderated mediation pattern is significant. Overall, in line with Spencer et al. (2005) findings, the observed moderation further supports our proposed mediating mechanism, and consequently our H 2 . In short, the effect of the perceived atypicality associated with a luxury brand's focus on sustainability on WTB is stronger for consumers characterized by a relatively higher NFU.

| Pretest
The objective of Study 4 was to demonstrate that the greater effectiveness of a sustainability-focused (vs. excellence-focused) communication on perceived atypicality and WTB manifests only for luxury products and not also for mass-market ones. Accordingly, we first pretested our stimuli through a paper-and-pencil study. In it, 98 undergraduate marketing students at a large European university (M age = 22.21, SD = .93, 53 females) were randomly assigned to one of four scenarios within a four-cell experiment that manipulated how a luxury product was described (emphasizing either its environmental sustainability or its excellence) and the product type itself (luxury vs. mass-market). Depending on the condition, respondents saw a picture of the same leather document folder (a unisex product) that was described as either sustainable (e.g., produced with no carbon emissions and employing plant leather with very low environmental impact) or excellent (e.g., made in a classic design involving very soft and top-quality leather), as well as framed as either a luxury or a mass-market product (we did not mention any brand name; see Appendix E). After reading the scenario, respondents indicated the extent to which they perceived the product as luxurious (1 = Not at all, 7 = A lot), as performance-or sustainability-oriented (1 = Performance-oriented; 7 = Sustainabilityoriented), and their attitude toward it (1 = Very low, 7 = Very high).
Finally, respondents were asked some demographic questions and were thanked for their participation.
A first one-way ANOVA, with luxuriousness perception as the dependent variable, confirmed that the product described as luxurious was perceived as significantly more luxurious than the same

| Method
We ran our main study with 220 respondents (

| Results and discussion
We first conducted two-way ANOVAs using product description (sustainable vs. excellent) and product type (luxury vs. mass-market) as factors and WTB as the dependent variable. The results showed that the interaction between product description and product type had a significant effect on WTB (F(2,216) = 41.19, p < .001). Planned contrasts revealed that when the product was framed as luxurious, WTB was significantly higher when the product was described as

| GENERAL DISCUSSION
In this study, we started from the core premise that consumers see a luxury brand's sustainability-focused communication as something uncommon and, therefore, atypical. However, we leveraged this atypicality to predict an apparently surprising outcome: that consumers manifest a higher WTB for a luxury product after being exposed to communication messages underlining that the related brand is engaged in product sustainability rather than product excellence.
We reason that the atypicality of luxury brands undertaking a Overall, this study presents interesting theoretical contributions.
First and foremost, we contribute to the literature on sustainable luxury consumption by introducing a new theoretical framework, grounded on perceived atypicality, to help explain consumers' decision to buy sustainable luxury goods. Importantly, our framework sheds light on the apparent paradox whereby consumers may be skeptical about the association between luxury and sustainability, but their WTB nonetheless increases in response to a sustainabilityfocused product communication due to the perceived atypicality of this focus for luxury brands. Relatedly, our work contributes to the literature on atypicality, which has mainly been studied in the context of brand and product management (Batra et al., 2010;Celhay & Trinquecoste, 2015;Loken & Ward, 1990;Landwehr et al., 2013;Schnurr, 2017;Talke et al., 2009). By contrast, we investigated the role that this construct might play in the context of luxury goods consumption. Finally, this study is the first, to the best of the authors' knowledge, to empirically compare consumers' reactions to sustainability strategies undertaken by luxury versus mass-market brands.
Previous studies have mostly investigated sustainability in the context of mass-market goods, and only rarely in the context of luxury goods, but never in unison (Athwal et al., 2019).
This study also offers interesting suggestions to luxury managers. First and foremost, our findings suggest that luxury companies could place their communication focus on product sustainability rather than product excellence. Indeed, we argue and demonstrate that consumers may react more positively to communication messages that highlight that a luxury product is sustainable (and in particular, has been produced in a way that does not impact the environment). Moreover, our results encourage luxury managers to partially revisit their traditional idea of uniqueness. While uniqueness in the luxury context typically stems from inaccessibility, prestigiousness and rarity, we suggest that uniqueness can also arise from the perception of atypicality generated by a luxury brand's sustainability focus. Our study helps luxury marketing managers understand why communicating sustainability can be successful for their products and brands. Rather than fear consumers' negative perceptions about luxury products' sustainability, our results suggest that luxury managers can gain benefits from highlighting the sustainability of their products, as this might increase perceived brand and product uniqueness-and consequently, consumers' WTB. Granted, we recognize our suggestions are only applicable to the current situation in the luxury market. When most luxury brands start following such recommendations, sustainability will no longer be seen as an atypical strategy in luxury. That said, our results offer an important insight for mass-market brands, as they underline that a sustainabilityfocused product communication is less effective outside of the luxury sector. Therefore, differently from luxury brand managers, massmarket managers should still prefer communicating their products by focusing on product performances.
While our research uncovered novel results that advance extant knowledge of sustainable luxury, it nonetheless features some limitations that might represent fruitful avenues for future studies.
First, we only considered the environmental dimension of AMATULLI ET AL.
| 13 sustainability, although previous work has shown that sustainability is a multidimensional construct that encompasses an environmental, economic, and social dimension (Huang & Rust, 2011). Future studies could therefore investigate whether our findings hold when also considering economic and social sustainability. Second, we compared the communication focus on product sustainability with the communication focus on product excellence, but we acknowledge that excellence in the luxury context is multidimensional in nature (encompassing "typical" luxury elements such as prestige, high-quality aesthetics, among others). Therefore, future studies could test if our findings hold when considering more specific excellence-related elements. Third, across our experiments we measured respondents' reactions in terms of their WTB and other behavioral intention measures (e.g., sharing likelihood). Future work could test if our effects hold also when employing more realistic behavior measures (e.g., actual purchases of luxury items). Fourth, an implication of our proposed causal effect of atypicality on uniqueness and WTB could be that atypicality has positive effects on outcome variables regardless of what the source of atypicality is. In our research, we investigated sustainability-focused communication as one source of atypicality, but there could potentially be other sources: low product quality, for instance, which would render our framework much less valid in a context (such as luxury) where high quality is considered to be a hygienic factor. While we partly addressed this concern by demonstrating that sustainability is a positively valued source of atypicality that has a direct positive effect on WTB, future studies might identify other positively valued sources of atypicality and compare them with sustainability to check whether the causal chain shown in our studies holds when considering other sources of atypicality. Additionally, although our results importantly reveal the benefits of communicating luxury products' sustainability, they do not capture whether this benefit changes based on luxury consumers' motivations. For instance, luxury research has widely demonstrated that consumers can approach luxury consumption with very different motivations, which can generally be categorized as external or internal (Amatulli et al., 2018;Eastman & Eastman, 2015).
The former approach emphasizes buying luxury goods to show status, while the latter mainly treats such goods as an expression of personal taste and style (Amatulli et al., 2015;Han et al., 2010).
Future work could investigate whether our results change depending on whether consumers have an internalized or externalized approach to luxury consumption. We shed light on the differentiated effect that a sustainability-focused communication may have in the context of luxury relative to the mass-market, but we do not consider other relevant product-related characteristics that recent literature (Amatulli, De Angelis, & Donato, 2020) suggests may play a key role in luxury consumption, such as the kind of appeal (utilitarian vs. hedonic) inherent to a communication message. Future studies could investigate whether the kind of product communication focus (sustainability vs. excellence) interacts with the kind of appeal used. Finally, we investigated the role of consumers' need for uniqueness, but we did not consider consumers' conspicuous consumption orientation-another consumer-related characteristic that converges with the one we observed and is also relevant in luxury consumption.
Other studies could test if consumers' status consumption orientation plays the same moderating effect as their need for uniqueness.

DATA AVAILABILITY STATEMENT
Data available on request from the authors.