Few concepts in the marketing literature have proliferated like the concept of attitude. However, a closer look at studies investigating attitudes as consumers' responses to marketing efforts reveals a considerable diversity in perspectives about the concept of attitude and its formation. Attitudes are considered either relatively stable object–associations, or temporarily constructed evaluations, which are formed through memory (cognitive)-based information processing or contextual and affect-based information processing. The current paper discusses and organizes these different theoretical viewpoints on what attitudes are and how they are formed. By approaching the topic through an integrative lens, the paper provides a solid conceptual foundation and roadmap for marketing researchers.