>One book may be borrowed hundreds, if not thousands of times. You over-estimate the lifespan of physical books and the physical stress of lending. 25–40 times

>One book may be borrowed hundreds, if not thousands of times. You over-estimate the lifespan of physical books and the physical stress of lending. 25–40 times is a more likely lifespan for a physical book. With digital lending, there are actually specific contractual limits on the number of lends and the cost per lend which vary based on the publisher. And the average number of lends per library book is probably close to 1.