Using data to track and manage student enrollment is steadily becoming a standard practice on both two-year and four-year campuses. Data mining enables colleges to create predictive models for identifying behaviors that put students at risk for dropping out, flag students who engage in these behaviors, and help identify practices that work in retaining at-risk student populations. Community colleges face particular retention challenges--both new and evergreen--that require creative ways of thinking about data-driven retention strategies. For example, as online-course enrollment booms for two-year institutions, online attrition follows suit. And tracking high-risk student groups (such as athletes) is a necessary but insufficient tactic to keep them enrolled on campuses where support services are stressed by limited resources. Here's a look at two community colleges that are successfully taking on enrollment and retention challenges. (Contains 3 online resources.)