The New York Times has a piece on David Mamet's decision to self-publish.
“Basically I am doing this because I am a curmudgeon,” Mr. Mamet said in a telephone interview, “and because publishing is like Hollywood — nobody ever does the marketing they promise.”
Mamet is publishing through his literary agency, ICM. But other literary agencies are launching (or have launched) similar services for their authors — many of whom publish their backlist titles this way. These "hybrid" authors assume more of the risk of publishing, but consequently also reap higher royalties.
“Increasingly, agents and authors tell us they are looking for options, and this model offers them a lot more than one size fits all,” said David Steinberger, chief executive of Perseus Books. With this system, he added, “they make the decisions.”