It’s time to take a closer look into the exciting and ever-expanding smartphone market. The NPD Group, a market research company, has done some number crunching for us to determine US smartphones sales for the first quarter of 2011. They break it down by smartphone manufacturer: Android-powered smartphones accounted for 50 percent of smartphone unit sales in Q1 2011 (falling 3 percent from last quarter); Apple’s iOS gained some ground jumping 9 percentage points to comprise 28 percent of smartphone sales; and RIM remains in a distant third place, dropping 3 percentage points to 14 percent for the quarter. Ross Rubin, executive director of industry analysis for NPD, explains Apple’s growth and Android dip (spoiler alert: it’s the Verizon iPhone’s fault): “Apple and Verizon had a very successful launch of the iPhone 4, which allowed the iPhone to expand its market share that was previously held back by its prolonged carrier exclusivity with AT&T. While some of that growth came at the expense of Android operating system (OS), Android models still accounted for half of all smartphones sold in the quarter.” Thanks to the iPhone being available on the world’s two largest carriers, Apple (14 percent) is now the third-largest handset brand in the US behind LG (18 percent) and Samsung (23 percent).

Here are a couple fun facts for you to chew on. This quarter marks the first time a majority (54 percent) of all new mobile-phone handsets purchased by U.S. consumers were smartphones. Woohoo, yay technology! And here are the five top-selling mobile phone in the country: iPhone 4, iPhone 3GS, Motorola Droid X, HTC EVO 4G, and HTC Droid Incredible. Go Apple and HTC!

[Via NDP]