I share your concerns about long term viability as well (and I download everything). I really want to see them succeed though... I've been thinking that a viab

I share your concerns about long term viability as well (and I download everything). I really want to see them succeed though... I've been thinking that a viable model that would keep courses free might be to use a kickstarter crowdfunding model to launch a course offering. If I did it, I'd set it up so that the threshold was high enough to make sure that the course was profitable, then make the course available to contributors first (and they'd get certificates), after which it would be freely available to anybody who wants to take it. You'd have to work out how to do the advertising efficiently so that it didn't eat your time and profits, which is probably a huge problem with the idea. Personally, I'd happily contribute to something like that on a regular basis though. Periodic relaunches could also be set up for certificate track stuff. You'd get the professor back in to answer questions and all that, but the video content could be left the same so it should be much less expensive to operate existing courses.