You are mistaken. They license their textbooks as “CC-NC-SA”. Their revenue model depends on students opting in to purchase alternate print and digital versions to the free, HTML version. They have gained traction, and will no doubt be rolled up by Bertelsmann sooner, or later. Remember, Bertelsmann owns Random House, and Random House sold its textbook division some years ago. Bertelsmann has been eyeing companies like Cengage and Houghton. FWK may be their new baby. The big question here becomes whether or not FWK’s affordability model (enabled by Open licensing) will be maintained once they’re rolled up. It’s often the case that when disruptive price plays are rolled up, they lose ground to the bean counters who just bought them. Bertelamann is not known for making, and then growing, successful strategic investments. This will be an interesting one to watch.

How are they going to make money if someone quite legally gives away what they charge for?

I guess they hope no one does? It’s dumb.