Coming off the Microsoft Point to Currency transition, Microsoft has upgraded their free Rewards Program.
Just like before, you can earn credits to spend in the Xbox Marketplace by being rewarded for things you are going to do anyway. Once enough “credits” are earned, they are automatically converted to digital currency and deposited into your Xbox Live account. Easy peesy.
For example, if you buy several Map Packs you can earn 5,000 Credits or if you renew your Xbox Live Gold membership you can earn up to 3,000 credits.
The biggest highlight is the rebate incentive for earning a high Gamerscore. Gamers with a Gamerscore of 75,000+ will earn a 3% rebate on all Xbox Live Marketplace purchases. And be sure to log in every month to take the free short survey to earn 250 Credits.
Learn all the details here: http://rewards.xbox.com/