One of the country’s largest convenience store operators, Circle K, has entered the contactless payments arena. It recently announced that some 1,500 of its 2,100 stores across the U.S. will now accept MasterCard PayPass.

According to MasterCard, the number of MasterCard PayPass cards and devices in market has grown from nearly 13 million from late 2006 to more than 50 million as of the fourth quarter of 2008. In addition, the Smart Card Alliance last September reported that nine percent of the U.S. population now has a contactless payment card or device.

About 94% of PayPass-using respondents to a 2008 MasterCard PayPass Benchmark Study were satisfied with their experience, and 77% said they use PayPass as their primary card for everyday purchases.