Generally not a lot, but if you do an event at a bookstore, or get some sort of promo deal, you can certainly move a stack of books all at once. (talesofthepack.com)
Plus, sometimes you can catch promo deals where you actually can get an even better deal. (uponarriving.com)
THEN: Schedule a 99cent promo deal with lots of ads. (creativindie.com)