Social media open up multiple options to add a new dimension to learning and knowledge processes. Particularly, social networking sites allow students to connect formal and informal learning settings. Students can find like-minded people and organize informal knowledge exchange for educational purposes. However, little is known about in which way students use social networking sites for informal learning and about characteristics of these students. In this paper, three studies examined the study-related knowledge exchange via StudiVZ, the German equivalent of Facebook. Results indicated that about one fifth of participants exchange study-related knowledge through StudiVZ and that these students are especially freshers seeking contact with other students and orientation. Consistent with previous research, it is shown that students use social networking sites mainly for social interaction and integration. However, results also imply that communication about social issues on social networking sites goes hand in hand with study-related knowledge exchange. (Contains 4 tables.)