NEW YORK (Billboard) - Apple's iTunes Music Store on Thursday launched Countdown to 10 Billion Songs, and is planning to give away a $10,000 iTunes gift card to the customer who buys the song that turns the counter to eleven digits.

In addition to announcing the giveaway, iTunes released a list of its all-time best-selling songs, making that information available for the first time ever.

Black Eyed Peas' I Gotta Feeling is Apple's most downloaded song, and its Boom Boom Pow holds the No. 3 spot. Lady Gaga also hold two of the top 10 spots with Poker Face and Just Dance. Other artists in the top 10 include Jason Mraz, Coldplay, Flo Rida, Taylor Swift, Leona Lewis, Ke$ha and Pink.

The complete list of the Top 25 best-selling iTunes songs of all time, and full details about the giveaway can be found on the store's Countdown page.