Previous work on MOOCs highlights both that the current MOOCs fail to provide the kind of social environment that is desired and that social interaction and exchange of support is important for slowing down attrition over time. However, little is known about how to support virtual teams in a MOOC context. In this paper, we demonstrate what factors distinguish successful and nonsuccessful virtual teams in NovoEd MOOCs, where team collaboration is an integral part of the course design. In particular, we find team leaders play a central role in determining team performance. We discuss implications for continued work towards intelligent support for team leaders in MOOCs.