Two years ago I made a joke at a conference about running an online course (we didn't have the term MOOC back then, young 'uns) using 4chan "as platform". It got a reasonable laugh, which was gratifying, although I was putting it up as a serious prospect for consideration.
For the last year, I've been trying to grok Reddit "as platform" - and failing, sadly. Well now the inevitable has happened. Welcome to The University of Reddit. With Reddit as platform. Obvious when you think about it. MOOCs will never be the same again.