
Today THQ revealed the purpose of that mysterious voucher code included in your copy of Darksiders. It's apparently a ticket to a bunch of free stuff.
The code entitles you to a free copy of either the Xbox 360 or PS3 version of Red Faction Guerrilla with the code. THQ is also throwing in a "digital Hellbook disc featuring Darksiders art, videos, and other awesome stuff." Even getting RF:G by itself would be money, though, as it's a pretty fun game. The links to redeem the offer are here.
While all that is technically free, you will need to pay $4.99 (plus tax) for the shipping. The offer is good only until March 7th. Only US residents are eligible for this deal.
Note that your free copy of RF:G doesn't need to be for the same platform that you bought Darksiders. I picked up the 360 version of Darksiders and am getting my free RF:G on the PS3.

CINEMABLEND NEWSLETTER
Your Daily Blend of Entertainment News
Staff Writer at CinemaBlend.
Joe Hendry Reveals How The WWE Snuck Him Into WrestleMania 41 For Randy Orton Match, And Confirms How Seriously They Take Surprise Appearances
Greg's Mom Seemed Like Another Nightmare 90 Day Fiancê Mother-In-Law, But She Changed My Mind
The Last Of Us Season 2 Episode 3 Live Blog: I'm Talking The Aftermath Of Joel's Tragedy, Ellie's Recovery And More