Apple's U.S. smartphone market share increased 3.5 percentage points in the three months that ended in May from the same period last year, according to consumer research firm Kantar Worldpanel. The iPhone accounted for 41.9% of U.S. smartphone sales in the latest period, up from 38.4% a year before.
That increase in market share aligns with the launch of the iPhone on T-Mobile, the last major U.S. carrier to begin selling the Apple smartphone. T-Mobile kicked off sales of the iPhone in April, midway through the three-month period, but the device still managed to be the carrier's top-selling smartphone during that time.
Kantar Worldpanel said the iPhone accounted for 31% of T-Mobile's smartphone sales. The Apple device is likely to account for an even higher portion of the carrier's sales in the current three-month period because it will be available the entire period.
The strength of Apple's iOS operating system "on T-Mobile appears to be the ability to attract first-time smartphone buyers, upgrading from a feature phone," Dominic Sunnebo, Kantar Worldpanel's consumer insight director, said in a statement. "Of T-Mobile consumers who bought an iOS device since it launched on the carrier, 53% had previously owned a feature phone, well above the market average of 45% of iOS owners who previously owned a feature phone."
As for other operating systems, Android's U.S. smartphone market share remained relatively unchanged during the latest period, while Blackberry saw a major decline to 0.7% from 4.6% a year earlier. Microsoft's Windows Phone increased its share to 4.6% from 3.7%.
[For the record, 5:10 p.m. July 8: A previous version of this story misspelled the last name of Kantar Worldpanel's Dominic Sunnebo as Sunnebos.]