Rational choice theory and its religious market model dominate sociological literature on megachurches. Common portrayals describe how these large congregations use corporate marketing techniques to sell religious consumers myriad products, including mega-sized worship and small groups. Recent developments at Willow Creek Community Church (South Barrington, IL)--America's flagship megachurch--reveal the emergence of a new product: the 'neo-parish,' which is both market-driven and steeped in principle. By transitioning from a 'church of small groups' to a 'church of communities,' Willow Creek seeks to find a middle ground between mega-worship and small groups. This new paradigm for group life prioritizes proximity over affinity--asking congregants 'where are you' before 'who are you.' Through an empirical case study involving 32 interviews, participant observation, and content analysis of organizational documents and sermons, I demonstrate how Willow Creek seeks to balance theological principle and market impulses in its quest to recapture the neighborhood emphasis of the parish system. Measuring customer demand and being 'seeker sensitive' are no doubt integral to the 'neo-parish' paradigm, which is consistent with rational choice theory and instrumental rationality. However, by using measures of customer demand in order to change customer preferences--challenging congregants to grow spiritually--Willow Creek operates in a substantively rational manner running counter to rational choice theory.