Scholars are aware of the power of social media to capture the attention of students, notably during lectures. Far from banning them, some teachers have considered using them to improve the motivation of students. One of the most popular social media platforms for that purpose is Twitter. It has been widely used in educational settings as a tool for collaboration and communication, but studies using Twitter as a tool to help students remember course concepts and stimulate their motivation to learn are scarce. In the present study, we conducted a three-year study in a ‘naturalistic’ educational setting using Twitter to remind students of course concepts, and asking questions every week during one semester. Comparing the groups of user and non-user students showed that this Twitter-based method elicited higher intrinsic motivation and interest in the course throughout the semester; importantly, it also reduced amotivation. Some benefits of using Twitter were also observed on learning and academic outcomes. We discuss the benefits and the limits of repurposing social networks for pedagogical activities.