"A couple millinia later (i.e., about a week), my agent called to tell me that S&S would not be offering a contract for any more books in the series. I was surprised. I won't say shocked. Times had changed since S&S had acquired the series in '07. The whole damn world had changed. I understood - even expected - a much lower advance. But no more books? Really? What was the reasoning? My agent quoted them as saying, "We think we've spent too much on these books already. We're not prepared to spend any more.""
You can read more here. The comments are also quite interesting.
This is a more honest and raw look at the book world than you'll normally see.
Is that honesty a good idea? I honestly don't know.