I think it was Pierre Dillenbourg, who once said that MOOCS are like marathons. You may find a map and run the Stockholm Marathon by yourself, but doing it together with some 20 000 other people is just more fun. With a crowd it is easier. People motivate each other.
It is known that only a small percentage of those who enroll to MOOCS complete courses. Several studies have shown that over 80% of the people doing MOOCS already have two- or four-year post-secondary degree. This means that the people taking MOOCS have trained to learn approximately 14-16 years before taking a MOOC.
Could it be that to study on a MOOC you must already be a good learner? You must know how to learn?
If this is true, the big question is how do you learn to learn? How do you you learn to study? How do you become a self-regulated learner?
What we know about learning and running. Training helps.