After my first novel was published many years ago (not Tor), I wrote polite letters to the editor trying to find out how many copies had sold. I never got an answer and eventually gave up trying. As you might guess, I had no agent. To this day, I don't know for certain how many copies sold or if it earned back its advance. I'm assuming not.

Thanks so much for helping demystify this whole process! Had I been less intimidated by the publishing end, I would have understood some of the reasons WHY they couldn't give me a number.