Another point to bear in mind is that, in Britain at least, authors get paid when their works are borrowed from public libraries. I don't know if this is the case in the US, but certainly in the UK there are a few popular authors who make the bulk of their income from libraries.

There was a huge fuss made by an authors' group a couple of years ago when the government tried to cut the already tiny amounts (a fraction of a penny per book borrowed) paid to authors.