Also, if my service is all-you-can-eat, I'm definitely going to take more risks with authors I haven't heard about. That is a definite win for unknown and unpromoted authors.
Some of the blockbuster authors may suffer lower revenues ... but fuck them. I'm less worried about JK Rowling who makes a billion dollars on each book, and already has plenty of incentive to write. I'm more worried about Professor Joe Schmoe, a Com. Sci. academic who has this really great AI story inside him, that needs just a little monetary incentive to come out.