The New York Times writes:
The print-on-demand business is gradually moving toward the center of the marketplace. What began as a way for publishers to reduce their inventory and stop wasting paper is becoming a tool for anyone who needs a bound document. Short-run presses can turn out books economically in small quantities or singly, and new software simplifies the process of designing a book.
As the technology becomes simpler, the market is expanding beyond the earliest adopters, the aspiring authors. The first companies like AuthorHouse, Xlibris, iUniverse and others pushed themselves as new models of publishing, with an eye on shaking up the dusty book business. They aimed at authors looking for someone to edit a manuscript, lay out the book and bring it to market.