The growth of digital coupons for loyalty cards is helping many small firms build brand awareness this year, according to a recent report from If the potential to boost a brand wasn’t enough reason for marketers to consider issuing loyalty cards, they may consider doing so in light of the recent addition of foursquare check-ins to CardStar – an application that lets users manage brand reward cards on their mobile devices.

CardStar announced its integration with foursquare today, explaining that when users scan their club loyalty cards at checkout they are now prompted to check-in at the business location on the geo-social site. Essentially, this approach offers marketers a double shot at consumer loyalty, drawing consumers to their businesses with the loyalty cards and turning these shoppers into brand advocates via the increasingly popular location-based social site.

“The typical CardStar user already launches the app at point-of-sale in retail locations, airports, gyms and libraries. The CardStar integration with foursquare was the next logical step to deliver a more cohesive mobile experience,” said Andy Miller, CardStar CEO. CardStar’s adoption of this feature indicates it is trying to leverage its brand among marketers with the geo-social site, which speaks to the rapid rise of foursquare as a marketing tool.

Foursquare gained 1.8 million worldwide users in its first year, and it may soon be powering search engines with real-time check-in data. This raises the stakes for the potential value of CardStar and other mobile apps that streamline consumer check-ins as foursquare updates could serve as word-of-web referrals for foursquare users and also countless online searchers trying to decide where to bring their business.