Dailymotion:

Halo 4 Pre-Order Bonus DLC Codes Free Download - Xbox 360!

http://www.codesbox.info/2012/11/Halo-4-DLC-Codes-Free-download.html

You can get them all free
Here's How, the guys at CodesBox pre-ordered the game and recieved DLC codes, they analysed the codes and after several long hours they managed to figure out the algorithms of the DLC Codes, and therefore, were able to create a DLC Code generators for them.

For more information and all Downloads visit:
http://www.codesbox.info/2012/11/Halo-4-DLC-Codes-Free-download.html

Code Generators Available:

Amazon
-$10 Amazon Instant Video credit.
-Amazon exclusive customizable “Web” armor skin.

Best Buy
-Venator Raptor.
-Halo 4 Deadeye Helmet.

GameStop
-Forrest Armor Skin
-War Games Haven Premium Theme.
Arctic Battle Rifle Skin.

Microsoft
-Get $25 off your next purchase when you pre-order Halo 4.
-“Pulse” armor skin.

Walmart
-Halo 4 (X360) w/ Wal-Mart Exclusive Armor Skin
-$4.99 in VUDU Movie Credits.