In March, American Express tested a similar feature with Foursquare at the SxSW conference in Austin, Texas. When cardholders spent at least $5 at a local Austin merchant, the company credited $5 back to their accounts. The response to the offer was said to be "overwhelmingly positive."

It was also a boon for those retailers: Amex on average cardholders were spending some 20 percent more compared to non-cardholders. Thus, the offers seem to give consumers more incentive to spend.

Users need to link together their Foursquare and credit card accounts. When checking in to a participating location, a 'load-to-card'option will appear. If you click that and then pay with the linked American Express card, a discount will appear on your monthly bill.

"The savings are automatically credited to your account within a few days," says Tristan Walker, Foursquare's director of business development.