New data from market researcher NPD shows sales of prepaid smartphones are increasing at a rapid pace. Smartphone sales overall shot up 42 percent in the first quarter compared to the same time last year with 36 percent of the unit volume increase represented by prepaid smartphone sales.

Broken down further, NPD found that year-over-year prepaid smartphone sales doubled in the first quarter. Postpaid smartphone sales grew 23 percent between the first quarter in 2012 and the Q1 2013. Vice president of industry analysis at NPD Stephen Baker said consumers focused their attention away from smartphone wars during the quarter and toward finding the best value for their dollar.

True enough, there weren't any major product launches for either side of the market in the first quarter. And of course, it helps that consumers are now able to purchase quality smartphones as part of a prepaid plan. As Baker points out, the Galaxy S2 and the iPhone 4S are two of the top five prepaid smartphones this year. Keep in mind, however, that these two models were among the top selling phones overall just a year ago.

Samsung claimed 32 percent of the top five prepaid smartphone sales during the first quarter. LG came in second with 22 percent of sales while Huawei claimed 11 percent. HTC and Apple round out the top five with eight percent of sales each according to NPD's Mobile Phone Track 2013.

Moving forward, NPD expects companies like AT&T to ramp up their focus on prepaid as evident by the recent announcement of their Aio branding initiative.