The iPhone 4S launch helped iOS gain a lot of ground and close the gap on Android. The two leading platforms were neck and neck in December, when most of the sales were generated. Windows Phone was the only other platform to improve its market position, but the Microsoft OS is still far from becoming a major factor in the US smartphone race.
Android accounted for 51.7% of all smartphone purchases in Q4, but its share in November and December dropped to 48.7% and 46.9%, due to the strong iPhone sales. The Apple platform had a market share of 44.5% in December, which is nearly double what it had in October (25.1%). The overall iOS share for the quarter stood at 37%