As per Pat Rothfuss: if someone uses this Bookfair code (11162161) when they make a purchase at B&N, Worldbuilders (a damned fine organization that raises money for Heifer International, which is also a damned fine organization) gets a piece of the action.
If you happen to use this opportunity to buy some of MY books, well, your karma increases tenfold. Or something.
Offer good in stores through September 2nd (September 7th online)
Here: have a printable voucher