I never really understood why it takes so long for Microsoft to implement their end of the deal on things like this. You can't tell me they don't have the capabilities to automatically detect when someone has spent X amount in X amount of time and automatically give out whatever it is they are giving away.
Then again, maybe we should just be glad that they are actually giving us promotions like these. Especially when you consider all the quality stuff that has come out in the past few months that people can now justify spending their hard earned space bucks on.