Hold your horses, peeps! This is Microsoft, a very reputable company. You paid for 6 months of gold, which you now have, and in a few weeks you will get an email with your codes for your five free games. Even if your gold subscription was half over, which it won't be, these games are yours to keep, even after the six months is up! I didn't get the deal, I keep waiting to see if it pops up on my dashboard, but I saw on another forum(slickdeals) that other people say that it said 4-6 weeks for the email.
It'll be worth it! ;-)