But Google’s Android mobile operating system fares well in the Midwest.

Nationally, 57% of U.S. mobile commerce transactions occur on a mobile device (smartphones and tablets) running Apple Inc.’s iOS mobile operating system and 43% occur on a mobile device running Google Inc.’s Android mobile operating system, according to a new study of 800,000 m-commerce transactions on hundreds of retailers’ mobile sites and apps. Online fraud prevention firm 41st Parameter conducted the geographic study of several hundred of its retailer clients, for the most part ignoring the less than 2% of transactions conducted on mobile devices running the Windows and BlackBerry mobile operating systems.

“It’s notable that the greatest concentration of iOS transactions comes from the most technology-forward states and regions: California and the Northeast,” says Ori Eisen, founder and CEO of 41st Parameter. “The fact that Android fares best in the middle of the country may have to do with people there being more interested in value than brand identification.”

In California, for example, 65% of m-commerce transactions occur on Apple devices and 35% on Android, the study finds. It’s not much different in the Northeast: in Massachusetts, 63% Apple, 36% Android, 1% other; New York, 62% Apple, 36% Android, 2% other; and Connecticut, 64% Apple, 35% Android, 1% other. In the middle of the country, Android fares far better: Iowa, 65% Android, 35% Apple; and Wisconsin, 58% Android, 41% Apple, 1% other.

The study confirms many current assumptions about mobile commerce; for example, Apple users shop more than Android users and have higher incomes, Eisen says.

“Many iOS device users are early adopters and so are more comfortable using their devices in a broader range of activities,” Eisen says. “Apple users have also tended to be more affluent people and so may simply be engaged in commerce more regularly than Android users. What’s more, Apple has conditioned its customers to spend online via their mobile devices through iTunes and the App Store.”