That's really rare. Back when I was in school the professor who taught the class and wrote the book would, every year, change enough of it to sell a new addition. Either move the sections around or change the problems.

Just so he could make more money.

It was a calculus class.

Fuck him.

Oh man. In undergrad I had a Thermodynamics professor who used the DRAFT VERSION of his textbook to teach with. It was completely unedited and he expected us to catch any errors. He was also like 80 years old, doddering, hard of hearing, forgetful, didn't give us a syllabus until halfway through the semester.... It's the only class in undergrad that I got less than a B in. Years later I still resent him lol

Ha hell yeah. My dad did adjunct work for a while while working for the gov. He declined profits from his textbook and gave it out free to his students as he thought it was unethical. The copies the gov bought for their cont ed courses he gladly accepted the profits from though lmao my dad's a real one.

It’s more of a grad school thing but I’ve had professors just give us all physical copies of their book because they have too many cases of free copies at home.