We donate a couple dozen books to the Lions every year, but our bookshelves remain overflowing. There are books on the shelf that I have read three times and intend to read again. The best ones require at least a second read. We also lend a lot of books to friends (and they seem to return eventually).
I have purchased lots of books after listening to radio or podcast interviews with people, and since I am unable to invite them to tea (dinner), I have to settle for time spent reading their thoughts on paper. Mind you, I did invite one author to lunch if her book tour should bring her to NZ; she graciously accepted, but alas, didn't make it across the big ditch.