authors seem less resistant to this than any other career field except programmers (who tend to do more "free" stuff anyhow... as they can get money by providing support).

The guy writing Robert Jordan's last wheel of time books (3) has posted his latest hardback online, in pdf format.

David Brin posts some free content online as well.

And there's always Baen Free Books, which got started on a bet ages ago.

I think it's because there have ALWAYS been libraries, and books are great word of mouth things...