Lack of social relationship has been shown to be an important contribution factor for attrition in Massive Open Online Courses (MOOCs). Helping students to connect with other students is therefore a promising solution to alleviate this phenomenon. Following up on our previous research showing that embedding a peer recommender in a MOOC had a positive impact on stu-dents’ engagement in the MOOC, we compare in this paper the impact of three different peer recommenders: one based on so-cio-demographic criteria, one based on current progress made in the MOOC, and the last one providing random recommenda-tions. We report our results and analysis (N = 2025 students), suggesting that the socio-demographic-based recommender had a slightly better impact than the random one.