(NECN) - EdX, based in Cambridge, Mass. offers Massive Open Online Courses, taught by professors from universities like Harvard and MIT. So far, more than a million students from all over the world have signed up.

For a very difficult Circuits and Electronics class at MIT, 155,000 students worldwide have signed up and 7,200 students have passed. The professors say he’d have to teach 35 years at MIT to reach that many people.

So it’s great for learners. But what’s in it for MIT? And is this sustainable as a business?

EdX President Anant Agarwal and Wellesley College X Associate Dean Ravi Ravishanker talk about the model.

See the attached video for the complete discussion.