Publishers do have lists. I read an article from an editor talking about how an author fired off a nastygram after being told that the editor absolutely loved the book, but can only give the green light to six books and all six slots had already been taken.
The editor and his followers thought the author should have felt flattered and heartened by the praise, but really, there are few things more devastating than reading that an editor would absolutely love to sign your book--but it ain't gonna happen...

Okay - although I'm wondering about the time frame for the six slots (or maybe that particular editor's 'allotment'). I just hadn't heard that reasoning before the last couple of weeks so I was curious about the 'authenticity'.
Thanks.

PS - too bad about the nastygram - that author probably sank any chance of getting into the next set of slots...