An author published by Macmillan did a write up about this on the Science Fiction and Fantasy Writers of America's blog: <a href="http://www.sfwa.org/2010/01/why-my-books-are-no-longer-available-on-amazon-com/" rel="nofollow">http://www.sfwa.org/2010/01/why-my-books-are-no-longer-avail...</a><p>You can probably skip the commentary on free markets, but he has some interesting insight in the actual cost and mechanics of publishing.  He explains that at the moment eBooks are the equivalent of selling limited editions of paper books because they just don't have the volume yet.