In a rather sudden but brilliant stroke of genius, Microsoft is giving new purchasers of Xbox 360 (before December 21st) a copy of Halo 3. A few basic catches, you have to hop on Xbox Live (which can be done with the free silver membership) and fill out the request form, and then the game is mailed out in January.

It’s pretty obvious this was a last minute move, since Halo 3 is not actually packaged with the console; Microsoft is whipping up the needed copies and mailing them out after the fact. That said, this is quite the deal, and since it’s based on your serial number, would stack with any other pre-Christmas bargains you come across. It seems only logical that this is a last ditch effort to keep 360 selling well throughout the holidays.

Now if they manage to market it properly, and get the retailers in on it, we could very well see a whole lot of new 360 owners who’ve just been itching on getting Halo 3, but didn’t mind the extended wait.

The registration page is currently down, but can be located here.