Kindle does let you share with another kindle. My sister does not have one. I think it is 10 days and while you are lending it, it is removed from your library.

Mine was bought for me as a gift and I would not have bought one for myself. I think if I had paid for it I would be trying to get my money's worth and using it like crazy.

I like the recycling part of used books. I only keep a select few books and pass the others on because I dont like clutter. That's why it works for me .