But as has been repeatedly pointed out by others, if your book doesn't earn out in three months or so, that initial payment is all you're going to get. (madgeniusclub.com)
A lot of books never earn out their advance. (jimchines.com)
Only 20 % of books earn out — and that's even with the modest advances of $ 5,000 — $ 10,000 generally offered to debut authors. (fantasy-faction.com)