One of the challenges in delivering MOOCs is providing quality feedback to your students. In the research literature, feedback, especially formative feedback, is identified as a strong predictor of student learning especially in developing deep understanding of core concepts. So the question is how do you provide formative feedback when you have 1000+ students and one or two instructors?
In the online learning space, social learning is one solution. How it works is you create a platform in which peers in the class can share their expertise and knowledge with other students in the class. There are many tools to accomplish this. You could have a tool that enables students to create professional learning teams in which they can conduct discussions and Q&As. Another tool is to create a peer-2-peer assessment features in which students give feedback on other's students works. The benefits of approaches like this is the platform cultivates a collaborative learning experience, instructors are able to coordinate feedback, and students are positioned as both learners and teachers. If you are looking for a best practice example in social learning I recommend NovoEd. I took the Crash Course on Creativity course and was super impressed by the user experience, course quality, and the in-depth collaboration features that were easy to use and very helpful in my exploration of creativity practices.