What would a day be without a little news about the iTMS? To celebrate the billionth track sold on iTMS, Apple is giving away a Nano and and a $100 gift certificate for every 100,000 songs sold (about 500) until they reach 1 billion songs. For the billionth track, the grand prize is an iMac, 10 iPods and a $10,000 gift certificate to iTMS.
If you want to try to game the system, try downloading iTunes Music Store Estimator to give you an idea where the numbers stand. Good luck.