Policymakers often advance charter schools as an education reform model that can offer more diverse educational alternatives for families. Yet, as these schools compete for students, questions arise about how they respond to the competitive incentives in differentiating themselves through marketing distinct options for learners. The way these schools promote themselves to their anticipated clientele--as opposed to how they are defined by their competitors--speaks to how schools engage and thus arrange themselves in the local education market. In that regard, school mission statements can offer critical information on the intended organizational purposes that differentiate each organization. Yet there is little empirical research on what these statements contain, and thus how schools respond to incentives in engaging local markets. This study looks at the content of mission statements--which are largely consistent with the schools' charters themselves--developed by each charter school in one of the most competitive charter school markets in the country: the Detroit metropolitan area. This study finds a notable level of isomorphism in charter school mission statements, indicating a tendency to replicate rather than innovate. This uniformity of mission statements suggests that charter schools are not fulfilling their potential in diversifying school markets.