This paper outlines the sources of legitimacy and distinctiveness for entrepreneurial ventures entering an emerging market category, particularly as they balance the tension to be “like” and “different from” their category peers. Using an inductive, mixed methods approach we find that new market category entrants imitate the organizational practices of an early, successful category member (a category prototype) while differentiating themselves with three types of organizational identity claims: (1) niche claims, (2) people claims, and/or (3) resource claims. Additionally, we find that the category prototype’s organizational identity and practices influence the collective identity of an emerging market category.