RESTON, Va. – The strongest growth in iPhone sales is coming from those earning less than the median household income because the Apple 3G device produces cost savings because it is used by this group as a single black box device replacing multiple digital services.

The ComScore study also shows that 43 percent of iPhone owners earn in excess of $100,000 annually �?? but sales among this segment are only a third of sales from the less well-off set.

According to a new comScore report, All about iPhone, iPhone adoption since June 2008 rose 48 percent among those earning between $25,000 and $50,000 per year and by 46 percent among those earning between $25,000 and $75,000. These growth rates are three times that of those earning more than $100,000 per year. Overall, iPhone penetration grew 21 percent.

“As an additional household budget item, a $200 device plus at least $70 per month for phone service seems a bit extravagant for those with lower disposable income,” said Jen Wu, senior analyst, comScore, the report

s author. “However, one actually realizes cost savings when the device is used in lieu of multiple digital devices and services, transforming the iPhone from a luxury item to a practical communication and entertainment tool.”

While the number of consumers in the $25,000 to $50,000 income demographic declined marginally from June to August 2008, their ranks among smartphone owners and mobile content users grew, in most cases above the rate of the overall market.

According to comScore Mobile, the number of people earning between $25,000 and $50,000 accessing news and information via their mobile browser grew by five percent since June, while the market overall grew by three percent. comScore also reported seven percent growth in mobile e-mail usage and five percent growth in mobile music consumption among those earning between $25,000 and $50,000 per year.

“These data indicate that lower-income mobile subscribers are increasingly turning to their mobile devices to access the Internet, e-mail and their music collections,” said Mark Donovan, senior analyst, comScore. “Smartphones, and the iPhone in particular, are appealing to a new demographic and satisfying demand for a single device for communication and entertainment, even as consumers weather the economy by cutting back on gadgets.”

More details on the demographics and usage patterns of iPhone users and related industry trends in the U.S. are available at Comscore.com/iphone

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