Microsoft's offering a great deal on Xbox LIVE Arcade during December. "Just purchase two qualifying games from Arcade between Dec'1-20 and receive 400 Microsoft Points-FREE!"
Eligible Arcade Games: Comic Jumper, Super Meat Boy, LIMBO, Plants vs. Zombies, Lara Croft and the Guardian of Light, Castlevania Harmony of Despair, Hydro Thunder Hurricane, Monday Night Combat, Blacklight: Tango Down, Toy Soldiers, Trials HD, Shadow Complex, Marvel vs Capcom 2, Battlefield 1943, Deathspank, Deathspank 2, Sonic 4, and Costume Quest.
To qualify for this special offer, you must register for offer using the same Xbox LIVE gamertag that you'll use for purchase. This promotion starts at 12:01 A.M. Eastern Time (ET) on Dec'1 and ends at 11:59 P.M. ET on Dec'20.
After purchasing two eligible Arcade games during the promotional period, the free Points will be either be deposited automatically into your Xbox LIVE account or sent to your e-mail via a token. Please allow four weeks for delivery, on or around Jan'17, 2011. Winning Microsoft Points must be used by Jun'30, 2011.
More Info: Xbox LIVE Arcade