alt Hacker News>And remember that so many textbooks now contain a mandatory online component where assignments get submitted and tests are taken, so you're forced to buy it even if z-lib has it. (I'm not defending that... just explaining it.)
It's a disgrace that universities are willing to use books that have been turned into consumable goods by single-use software or usurious saas rental messes.
Yes, this is how textbook manufactures sell to university. One time codes for online exercises / labs. This happens mostly for intro classes. I have no idea why universities do this, my guess is they are sold on hw problems being randomized so it makes cheating more difficult.