What is a "print publishing farm"?
Some print publishing houses, typically based in countries other than the United States but not always, solicit material from institutional repositories such as theses and dissertations. An "acquisition editor" (or some similarly titled person) will contact the author with an opportunity to turn the digital thesis/dissertation into a printed publication, however, the experience of this Slate.com author shows the shadowy side of such publishing houses, or "print publishing farms."
Be wary of unsolicited proposals for publishing your academic work. Do a little research into the operations and reputation of the publisher in question.