I guess it makes the certificate itself seem more valuable as a means of expressing that you accomplished something. My view of edX is biased though by how awesome CS50 is, it feels more like a movement than a class.

Please don't compare. I don't give a damn about certificates, and I think it's totally fair for them to be paid. Actually, as I think it's only normal to not give a damn about certificates, I'd say even some kind of "full track" with exams is ok to be paid for. They still provide good learning material for free.

And, by the way, the quality of the course material on edx is arguably better. It's a shame that coursera's got way more recognition somehow, apparently.

edX is a non-profit, and the majority of our code is open source. However, course content belongs to the course creators—professors and universities. We have agreements in place to keep most content public, and re-run courses, for multiple years in some cases.

Learners who want a verified certificate but need financial assistance can learn more at https://support.edx.org/hc/en-us/sections/203392988-Financia....