Apple's App Store opened on July 11 along with the iPhone 3G launch, and third party application downloads have already topped 25 million. According to the company, the iTunes-based store already has over 900 applications available, and more than 20 percent of those are free.

The built-in App Store customer base has been growing substantially with over six million first generation iPhone owners and now over a million iPhone 3G owners as potential customers. The iPod touch -- one of the strong drivers in the company's third quarter iPod revenue -- is also App Store-compatible and is contributing to application downloads, too.

Application price is likely helping to drive app sales, as well. "More than 90 percent [are] priced at less than $10," according to CFO Peter Oppenheimer.

He added "Customers are really loving the App Store."

The App Store hosts Apple-authorized third-party applications for iPhone, iPhone 3G and iPod touch users. The online store offers games, productivity and business applications, music apps, social networking apps, and more.

Apple takes a 30 percent cut of every application sold, so if current App Store popularity holds, it could prove to be a strong revenue generator for the company.