Peer recommender systems (PRS) in MOOCs have been shown to help re-ducing attrition and increase performance of those who use them. But who are the students using them and what are their motivations? And why are some students reluctant to use them? To answer these questions, we present a study where we implemented a chat-based PRS that has been used during a MOOC session involving 6,170 students. Our analyses indicate that PRS-users are students unsatisfied by other means of interactions already availa-ble (forums, social networks…), and that they seem to use it more to share emotions than to learn together, or to assess their progression against their peers.