"As of this morning we have 68,000 students enrolled in Introduction to Databases, and the number is growing daily. Wow!! The reception has been way beyond expectations -- we're pedaling like mad to keep up, and having a great time. Please visit the Q&A Forum if you have questions, or if you have answers! With a class this size we're certainly relying on students-helping-students. Welcome aboard."
It seems there's demand.
The demand is very high, and all three of these are fairly specialized classes.