Sorry, I don't want to appear as a kiljoy on this one, but what the hell.
Sounds like it could end up to be a bit of a logistical nightmare as someone would need to maintain a central database to keep track of all the books available & where they were at any time, send out reminders etc. Obviously books can be heavy items & therefore expensive to post & people could end up seriously out of pocket. Then there is the problem if a book gets lost or damaged & once it has passed through 150 pairs of hands it is going to be knackered so who will replace it? If it's a rare one it might be impossible to replace.
Sorry for so many negative waves, it's a good idea in theory though.