UPI story here. This is a telling statement:

The firm estimated renting textbooks cuts the cost of school books in half, if compared to buying a new textbook.

Great, but what about compared to buying a new book and selling it (online or at the school bookstore) in good condition at the end of the term? Buying a used book and selling it?

We won’t make textbooks truly less expensive until we solve the third-party-payer problem: When the person making the buying decision (the professor) isn’t the person who forks over the cash (the student), costs spiral. See health care.

Why not give each professor a budget for books, and let him keep some proportion of the unused money? The remainder could go either to the students in the class, or into the college’s general budget.