"We started to see Android take off in 2009 when Verizon added the [Motorola] Droid," said Ross Rubin, the executive director of industry analysis for the NPD Group. "A big part of Android success is its carrier distribution. Once it got to the Verizon and Sprint customer bases, with their mature 3G networks, that's when we started to see it take off."
According to NPD's surveys of U.S. retailers, Android phones accounted for 44% of all consumer smartphone sales in the third quarter, an increase of 11 percentage points over 2010's second quarter. Meanwhile, Apple's iOS, which powers the iPhone, was up one point to 23%.