Yes, I'm guilty of that too. The main reason I don't take more courses is the time it takes to take them. I've taken 3 courses (databases, algorithms I & II), and they were all great, but required a lot of work. So while I'm tempted to sign up for more, I need to have the time available to take them too. This is similar to buying books, but not having the time to read them (something I'm guilty of as well ;-))
I sign up for a lot of courses, but I drop maybe half of them a week in. Usually because it's more work than my casual interest in the subject warrants.
On the other hand, since these things started, I've finished 12 courses in a variety of fields.
I'm signed up for 5 classes starting in the next couple months, I'll probably finish maybe 3 of those. We'll see. :-)
Most of it in my case is learning for its own sake, but MOOCs are just about the best part of the internet for me. I took a Neural Networks class from Hinton and there's an upcoming class on Financial Markets from Robert Shiller. It's hard to beat that kind of access to teaching by absolute leaders in their fields.
I sign up for a lot of these, but am only interested in the material offered, not actually taking the course. Because of this, there are courses I never revisit, I just sign-up to save them for future reference.
my completion rate is somewhere around 30%, mainly because some courses are not what I expected to be, or I realize I'm not that interested in the subject.
