Earlier this month Apple announced that iTunes would soon reach 10 billion songs downloaded. After nearly seven years of operation, the iTunes Store will finally reach that milestone tonight. To celebrate the milestone, Apple is having a promotion where you can win $10,000 iTunes voucher if you happen to download the 10 billionth song.

The iTunes store has evolved quite a bit since it started. Originally they only offered music locked down with FairPlay (Digital Rights Management) software. The lock frustrated users who demanded the freedom to play their music on any device. Eventually they announced that all music would be available DRM-free.

Apple also added new stores since the launch: Audiobooks, Video (Movies and TV), iTunes U, and eventually the App Store after the iPhone OS 2.0 firmware was released. Since launching the App Store in 2008, there is now 150,000 applications available for download for the iPhone and iPod Touch. Over 3 million applications have been downloaded so far. The App Store sales have been so successful that Apple launched an ad campaign that coined the phrase “There’s an App for that.”

With the upcoming release of the iPad, they have announced that they will be adding the iBookstore, which will allow users to download electronic books, named iBooks, to their iPad. Unfortunately Apple has kept quiet about is what it plans to do with the recent acquisition of Lala. Many rumors have circulated about what Apple plans to do with the new talent, like adding cloud support to iTunes. For the moment though, they will certainly be celebrating the milestone of 10 billion songs downloaded.