As we’ve discussed in this space before, sales figures are one of the great mysteries of publishing. Unless you have a Neilsen BookScan account, you’re pretty much playing a guessing game about how much this person sold versus that person.
Moonrat’s response? 7,000 hardcover copies sold. Read the entire post (and comments) for explanation of that figure. I’m not sure that I can refute or agree with that assertion, but it is an interesting statistic and the comments discussion is lively.
Naturally, this is going to vary from case to case. If you are an extremely esoteric writer, then your editor might be thrilled at selling 3,000 copies. If you are Charles Frazier and you just cashed an $8 million advance for a book that won’t earn back half that amount, your editor will probably be drinking heavily.