The tremendous popularity of social networking sites like Facebook presents libraries with unique opportunities for reaching students. What many organizations fail to realize, however, is that Facebook is perceived by its users as a primarily social (would "recreational" be better here?) space, and that the presence of professors, librarians, or parents can be intrusive, unwelcome, or just plain "weird" for the very students they're trying to reach. The George Washington University's Gelman Library decided to take a step back and ask a critical question: what do our students want? That is, how do our students really use Facebook, and what part can the library play in this social environment? Gelman librarians worked with an anthropologist to conduct a mixed methods study of students' use of Facebook, focusing on the intersection of students' academic and social lives in this platform. By identifying the unspoken rules and patterns of behavior, the researchers made recommendations for Gelman's Facebook initiatives. This presentation will offer an overview of this study and its findings in light of contemporary thinking and practices among (technologically savvy?) librarians. The study's recommendations bear critically not only on existing literature about Facebook and libraries, but also on popular assumptions about online social networks. A discussion of Gelman's experiences in implementing and refining its Facebook campaign will facilitate a broader consideration of the opportunities social networking sites present for libraries, and the merits of anthropological research in evaluating these new, "social" technologies.