I've been doing Coursera courses for the past few years in an on/off fashion. I'm pleasantly

surprised by the courses that are more popular in this list.

I think the pattern is that the foundational or introductory courses are popular as they have a

larger audience. But it doesn't comment on the quality of the course. An interesting data point

is the social media "Share" widget that appears on the right column [0].

[0] https://www.coursera.org/course/rprog