RoganSarine is correct but one thing to remember: Amazon.com only gives the credits for the FIRST order of a particular item. So if you want to order a game, please check the GYROS page or ask me directly if anyone has ordered it yet. I'd hate to disappoint you with not getting the discount.
I will try to keep track of these things for you ^_^ And yes, I give you the credit instantly as long as nobody else has claimed it. Thanks!