Apple's iPhone user base is now the second-largest in the U.S. smartphone market, passing Windows Mobile-based models to slip into the spot behind Research In Motion's (RIM) BlackBerry, research firm comScore said today.
In the three months ending in October, Apple 's iPhone was used by nearly 9 million Americans as their primary phone, said Mark Donovan, senior analyst with Virginia-based comScore.
That compared with the almost 15 million who identified RIM as the maker of their primary smartphone in the monthly surveys comScore conducts of U.S. mobile subscribers over the age of 13. Phones powered by Microsoft 's Windows Mobile, meanwhile, were used by an estimated 7.1 million people during the same period.
According to comScore, approximately 36 million Americans own a smartphone, while around 196 million rely on a traditional cell phone.
"The surveys aren't a measurement of sales velocity in the last quarter, but of the installed base using the phone as their primary," cautioned Donovan, who acknowledged that the iPhone has been outselling Windows Mobile phones for some time. "But there has been a large installed base of Windows Mobile phones out there, which accounts for its strength until recently."
In the three months ending in July 2009, the iPhone and Windows Mobile were neck and neck, with a user base of 6.63 million and 6.66 million, respectively.
And Windows Mobile is in for some more hurt, said Donovan, citing a report comScore issued today that said prospective smartphone buyers were predominantly leaning toward buying iPhones and Google Android-based phones in the next 90 days. According to that data, 20% of those who said they planned to buy a smartphone in the next three months pegged Apple's iPhone as their intended purchase, while a total of 17% identified an Android phone -- 8% tagged Verizon's Droid , for instance -- as their expected buy.
Donovan credited Verizon's Droid advertising for increasing consumer awareness of Android-based models, which had garnered only a 7% share of the future purchase plans as recently as July.
"There's some serious momentum behind Android," said Donovan. "The iPhone and Android have set the bar at a new high for smartphones."
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld . Follow Gregg on Twitter @gkeizer , send e-mail at email@example.com or subscribe to Gregg's RSS feed .