Apple sold 1,130,000 computers in the U.S. in the first quarter of 2010, according to IDC, a figure that represents 6.4% of the market.
But the popularity of Apple's iPod, iPhone, and now iPad lines means that the company can count 21.6% of adults nationwide among its customers, according to a new report from Experian Simmons. And that's to say nothing of those under age 18 who use Apple devices.
In many urban areas of the U.S., Apple's presence is stronger still.
The top geographic market for Apple is where it makes its home, in California's San Francisco Bay Area, including Oakland and San Jose. Almost one-third of all adult residents of the Bay Area own at least one of Apple's three core products: Mac, iPhone, or iPod.
Of Apple's top 10 regional markets, according to Experian Simmons, four are in California.
Beyond the Bay Area, where Apple product ownership is 49% above the national average, the three other Apple strongholds in California are San Diego (#3), Monterey-Salinas (#8), and the Santa Barbara-Santa Marina-San Luis Obispo region (#9).
In the San Diego area, 31.8% of the area's 2.2 million adults are "admitted Mac users," Experian Simmons notes, as if that were something to conceal.
In the Monterey-Salinas area, home to about half a million adults, about 151,000 or 28.1% own a Mac, iPhone or iPod. And there's only one Apple retail store in the vicinity.
The Santa Barbara area, meanwhile, is home to 141,000 Apple customers, or about 27.9% of area adults.
Other top Apple strongholds include Boston, MA (#2), New York, NY (#4), Washington, D.C. (#5), Chicago, IL (#7), and Las Vegas, NV (#10).