If lending is the appropriate mode for books, then how would the business of publishing look if it is built around lending rather than ownership? So here is my conjecture. All books are read on devices. Imagine that each device has built in a means of tracking what people read and how much. Imagine that it can also do this in a manner that respects privacy. Then the model I have in mind would allow publishers to receive money based on how much of a book people read and to price that at will.
I like the idea. One point of comparison is to the way radio works. In radio, the content is not DRMed, and you don't pay for each song you listen to. Instead, you subscribe in bulk to content and then flip around to whatever you feel like listening to. There are a variety of specific payment schemes on both sides of the arrangement. For the customer, I've encountered payment based on public taxes (Switzerland), by subscription (Sirius Radio), and by listening to ads (broadcast in the U.S.).
For the content producers, I am less clear about what contracts are out there. At least indirectly, however, they are paid more when there are more users listening to them. I imagine that radio has the same sort of marketing research that television does, and that radio stations know how many people are listening to their station and at what times. They then, through mechanisms that are probably kludgy, buy more of the popular music and less of the unpopular music.
It's a good idea, and I would be happy for it to catch on. Copies are trivial to make, nowadays, so the only ways to control copies are rather draconian. Far better to put a good society first and then find business models that work with it.