The study's main aim was to explore the role of Facebook class groups, created and managed by high-school students, in facilitating social dynamics and learning experiences. Fourteen Facebook class groups were observed online and students were subsequently questioned through focus-group interviews. Our findings show that Facebook class groups can promote both bonding and learning. Bonding can be enhanced because Facebook class groups foster a sense of solidarity and unity among students. Also, Facebook can stimulate (social) learning because students gain more insights in the subject matter and are challenged to carry out an evaluation of their own study methods and progress. Therefore, drawing on the theories of seamless learning and affinity spaces, we conclude that Facebook class groups are important for social affiliation and effective learning.