Mobile marketing app shopkick already works with more than a dozen big name retailers including Target Corp. and American Eagle Outfitters on a program that lets retailers transmit rewards such as store credits and song downloads to shoppers’ smartphones when consumers enter stores or take such shopping actions as scanning bar codes on items with their phones.

In its latest marketing move, shopkick has cemented a new relationship with MasterCard, opening the way for the payment card brand to roll out shopkick and its proprietary reward currency, kicks, to more retailers and MasterCard cardholders.

In making the announcement, shopkick and MasterCard didn’t say how many MasterCard-affiliated retailers or cardholders are expected to participate in the program. But under the new marketing partnership, consumers can link their shopkick app to a MasterCard and receive rewards points each time they pay for qualifying purchases with their linked MasterCards at participating shopkick retailers. Additionally, consumers who sign up for the new program will receive 250 bonus rewards points for each MasterCard they link to shopkick.

In recent months, shopkick, which launched in 2009, has added new merchants such as Target, No. 31 in the Internet Retailer Mobile Commerce Top 300, American Eagle (No. 102), Best Buy Co. (No. 16) and ExxonMobil. The marketing alliance with MasterCard will potentially expand shopkick’s network to include a much large universe of retailers and mobile shoppers, says shopkick CEO Cyriac Roeding. “Over the past nearly two years, we have expanded our partner network of retailers, brands and financial partners to create the most powerful coalition rewards program in the U.S.,” Roeding says. “The addition of MasterCard significantly increases shopkick’s reach and its benefits to cardholders and partner retailers.”

The shopkick app detects a signal emitted from a small device about the size of a brick located in each participating store; the signal is picked up by a shopper’s smartphone when the app is open. Shopkick then delivers kicks to the consumer’s account, rewards points that can be collected and redeemed at all participating locations or for movie tickets and other items. In addition to getting kicks for walking in to a store, consumers can get rewards for doing such things as scanning bar codes on posters in dressing rooms or on items, and now, for paying with a linked MasterCard.

The way a shopper redeems a special store offer presented through shopkick depends on the retailer. With an American Eagle campaign, for example, consumers clicked a “Use it” button in the app to apply the offer. When she was ready to purchase, she clicked a “Checkout” button to display a discount code to present to the cashier. In a Best Buy partnership, a shopper informed the cashier that she was a shopkick user and provided her cell phone number. Then, any applicable shopkick discount was deducted and appeared on the shopper’s receipt.

Shopkick gets paid a small fee for each kick a store doles out. If a consumer buys an item after using the app, shopkick gets a percentage of the purchase price, the company says. There’s also a fee for the shopkick signal transmitters, which a spokeswoman says cost less than $100 each.