Apple's iTunes music store has played a large part redefining how we think about purchasing music. Since its launch back in April 2003, the iTunes store has shifted a huge number of tracks, reaching the 6 billion milestone back in January 2009. Now Apple is counting down to a new milestone, that of 10 billion song downloads. As a way of celebrating this, Apple is running a competition and will be awarding a $10,000 iTunes gift card once the milestone is reached. You are limited to 25 entries per day and you must be 13 or older to be eligible (you can find the full rules here). Downloading a track at the iTunes store gives you an automatic entry, though if you don't want to buy tracks to enter then you can use the entry form here. The counter is slowly edging its way toward 9.9 billion as we speak and if my calculations are correct (and they may not be, feel free to correct me), then it is possible the target could be achieved by early next month.