When I speak to an audience of publishers, I use Getting Real as an important example of how popular bloggers who want to publish can easily skip publishers all together. 30,000 copies of a self-published PDF @ $19 (with no incremental unit cost) implies some enviable margins.
Tim Spalding over at LibraryThing brings up an unintended but important consequence of skipping publishers, especially when the resulting book becomes culturally important: right now it’s also skipping libraries:
OCLC’s WorldCat records exactly three copies—MIT, California Polytechnic and the University of Nebraska. That’s three copies of one of the top tech books of the 00′s in most of the US libraries that matter. The Library of Congress? New York Public? Harvard? None of them. For comparison, WorldCat contains 619 copies of Solitary sex : a cultural history of masturbation.