As part of the promotion, Borderlands 2 and its content are currently on sale for up to 75% off. You can grab the single game, sans DLC, for $4.99 or double down for $9.99 and nab the Game of the Year Edition, featuring bonus content.
If you're a forward thinking player, this week Steam has opened pre-orders up for the next installment in the series, Borderlands: The Pre-Sequel. Launching October 14, The Pre-Sequel is coming to PC, Xbox 360 and PS3.
Borderlands 2 (7/13/12)