[waitingkuo]

Disclaimer: I've paid for many courses but never paid for a specialiazation.

I personally don't care about the effect of the certificate. I paid simply because what instructor taught me worth more than it cost.

[siosonel]

Same here. For example, I was not planning to pay for Andrew Ng's class. But at the end, I've learned a lot and enjoyed his style of teaching, and figured that by paying I was helping support his mooc course for others to enjoy as well.

[eecks]

What courses did you do?

[waitingkuo]

Most of them are about Data Science / Machine Learning and some math stuff