Shortly after the release of Darksiders we posted an article speculating on what the voucher included in the initial run of the game was going to give to gamers. Finally, for those of you who have held on to your voucher, its redemption goodies have been revealed. You can redeem your code for a “digital Hellbook disc featuring Darksiders art, videos, and other awesome stuff” which inlcudes a free copy of Red Faction: Guerilla.
All you have to pay for is the postage stamp and you are good to go. You must live in the US to receive it and be sure to send it in by March 7th since that is when the window closes on this deal.