Literature on new product development indicates that on average around 40% of new products fail across different industries (e.g., Crawford, 1977; Crawford and Di Benedetto, 2008). Out of those that survive only few become widely accepted standard equipment in the industry (Utterback, 1996). Literature on entrepreneurship (e.g., Baron and Shane, 2008) and on innovation (e.g., Christensen, 1997) shows that such innovations often originate outside the boundaries of established firms. However, it is difficult to understand and analyze the exact source of such innovations and the entrepreneurial processes by which they are developed. It is therefore the aim of this study to shed light on how innovations become widely accepted by large segments of the market and specifically which demand-side forces are at work. An approach suitable for pursuing this objective is to focus on those individuals who are on the leading edge with respect to an important market trend (lead users) and their respective peer communities. As little knowledge is available, an explorative case study design is applied, working with cases from two different industries, specifically the medical equipment and sporting equipment industry. A longitudinal research design is used, extracting data from multiple respondents and various other sources such as reports, publications, databases, or community web pages. The research framework takes a process perspective by following the entrepreneurial processes from invention to commercialization and diffusion. In this process, micro-level variables at the individual and group level are analyzed as well as the barriers to be overcome by the individual innovator and the community. The findings show that communities play a central and active role in the entrepreneurial process. Community members provide valuable feedback on the overall potential of the lead users' ideas, participate by making concrete development contributions, acting as testers of the new products, and finally helping to diffuse the innovations inside and outside the community. We identify two pull effects on the part of the community: first, community members demand and facilitate the development of prototypes; and second, community members help to cross the chasm between first adopters and the early majority. This paper has various implications for entrepreneurship and innovation research. For entrepreneurship, this article points out peer communities as a specific kind of social network that plays a crucial role in entrepreneurial processes. For innovation research, this article emphasizes the interaction between lead users and their peer communities in the process of developing the next dominant product design.