Apple's iTunes serves up 10 billionth song download

The momentum for iTunes has only accelerated since the store first opened in April of 2003. It took nearly three years for Apple to achieve its first billion in sales, while the 3 billion milestone was reached in July 2007.

Apple reached the halfway point to Wednesday's 10 billion milestone in June 2008. While the 5 billion mark took more than five years to reach, the next 5 billion came in less than two years, just after 4:30 p.m. EST Wednesday.

To accompany the 10 billion achievement, Apple did a promotion awarding a $10,000 iTunes gift card to the person who downloaded the song.

Wednesday's milestone also happened to coincide with the birthday of Apple co-founder Steve Jobs. The technology titan is 55.

In August, Apple's iTunes was found to be a quarter of all music sales in the U.S. That makes iTunes by far the largest music retailer, ahead of second-place Walmart with 14 percent. In all, digital downloads make up 35 percent of music sales, and iTunes accounts for 69 percent of online sales.

The future of iTunes could be very different. After Apple's purchase of music streaming service Lala, the Cupertino, Calif., company is expected to shift towards the browser with a cloud-based service that could let users access the content they own from anywhere, on any device.

Apple has also been slowly expanding its browser-based iTunes Preview service, which allows users to explore content from the online store without launching the iTunes application. It is rumored that Apple will eventually allow customers to access and buy content from the browser.