PG-TRAK90 is a cluster-based geographic marketing system designed by Maryland's Prince George's Community College (PGCC) to maximize educational marketing objectives. To create it, United States Census Bureau files containing over 200 demographic, housing, and lifecycle variables for 172 tracts in Prince George County (PGC) were reformatted into marketing-style indicators and subjected to a statistical sorting technique known as cluster analysis. The result was a typology of PGC neighborhoods sorted into 22 clusters based on geographic, socioeconomic, and ethnic categories, including the mostly white, upscale business executives in the "exurbs"; Black Middle America; and the inner suburban mix of young Black and Hispanic families, among others. To determine how well PGCC draws students from across this demographic spectrum, clusters-in-the-county were compared to clusters-in-the-student-body revealing that as of 1990, the student body closely mirrored the county demographics. An analysis of market penetration by cluster revealed that upscale groups sent proportionally more students to PGCC than downscale clusters. Credit versus non-credit course markets were also analyzed for 1985-90, indicating similar proportions of enrollment by cluster in both types of courses. PG-TRAK90 is incorporated directly into PGCC's student recruitment efforts and will provide critical market analysis and contact targeting. (KP)