I read an interesting article today by the author Oisín McGann. In it he lays out the logic behind releasing a free ebook to publicize his other works.
Irish Publishing News: How to Make Ebooks and Influence People.
The ebook is still available and is linked to in the article, but I'll stick it in here too:
The Vile Desire To Scream
I thought his explanations about concepts like why there are different formats and the minefield that is free vs spam, were excellent. And I found it interesting that even though it was "self published", he still needed a team of people to help him. Even in a paper-free world, I guess we'll still need editors, programmers, illustrators and publicity experts!