Over the last few years I’ve seen an increase in authors creating blogs for their books, some posting portions of their books online for input from others. This has the benefit of creating a book that meets readers' needs while also building some word of mouth. Some authors are probably not as comfortable with such an active process. O’Reilly is taking this idea a step further and creating a revenue stream with it. You can buy into the “rough cut” and either get only the “beta” version for fairly cheap or get both the beta and the print version when it comes out. This is an interesting idea as people who don’t buy computer texts due to the cost may be willing to buy a cheaper pdf version even if it’s not completely finished. It also allows people to be engaged in the publishing process which may attract others. From the about page:

Rough Cuts content usually becomes available anywhere from two to six months prior to a book’s publication. It’s updated as the author and technical reviewers progress, so you’ll have access to new versions as they’re created. Chapters won’t necessarily be written and posted in the order in which they’ll appear in the published version.