[quote name='sickman']The Tomb DLC code expires on 8/21/13. You have to enter it at the website, then they will post your Xbox Live redemption code. Remember to enter the dash, or it won't work![/QUOTE]
Thanks for posting this! Also, there was a pair of what I thought were zeroes (00) in my code, but when I tried to redeem the code on darksiders.com/tomb it said it was invalid. I changed them to the letter O (OO) and the code worked.

So, if someone tries their code and it doesn't work, try replacing any zeroes you are using with O's.
I went ahead and redeemed the code for Argul's Tomb and the Crucible Pass, better to do it now while I'm thinking about it, I figured. I loved the first Darksiders, so I'm honestly pretty psyched about getting the second game at such a low price.
Also, mine was not the "Best Buy LE" (which I've never seen, I guess if my store had any they only received a few) but the "regular LE".