Selling course notes: a market solution

Should it be ok for students to take notes during a class and turn them into a marketable product that they make money on?

If I am teaching the same class again this year, students could buy the course notes and potentially do better, or learn more. That's a good thing, right?

However is it fair to me? After all these students are becoming multi- millionaires by reselling my work, my intellectual property. Yeah right.

One professor has an amusing solution to this dilemma, but I think it still misses the point;

Precisely. Besides which, I've figured out a much more fun solution to the problem: I'm going to buy some of these note sets and outlines being sold for my classes. I'll go through them and find all the mistakes. And then I'll write exam questions testing on those very same mistakes. If we all did that, the market would dry up pretty quick. (from Professor Bainbridge.com)