As part of The Big Clean and a study month that I haven't quite named yet (the two events are sort of overlapping), I am trying to go through all the back messages in my listservs. I just found an e-mail at Adbooks with a link to Waiting for It, an essay that explains why there's such a long wait between a manuscript's acceptance and its publication as a book. In a word, it's all about marketing.
Waiting for It spells out what I think can only be described as the struggle to sell a book. It also explains what traditional publishers do for authors, or try to do for them.