You use the code on the webpage listed on the card. It is for more stuff. If you actually go to the page and read what it says then you would know what to do.
But since I am nice this is what it says:
Redeem your Founder status:
- Sign-Up for a Call of Duty ELITE account
- Upgrade to a PREMIUM membership by November 13th, 2011
- Play MW3 multiplayer. You will automatically become a Founder.
Please allow up to 48 hours for your Founders status to appear in MW3 and ELITE. Founder status will be indicated by a green skull next to your name on your Career page on ELITE.
If you have a MW3 Hardened Edition you can use the code included on the Founder card to add Founder benefits to your Premium account on the site after 11/13/11
