How does the merchant (the store that provides the deals) keep track of the deals redeemed?
Your merchants are provided with a login option which gives them access to their own dashboard area of the system. From here your merchants are able to download a manual tracking list of outstanding vouchers. Or view the coupons purchased, and change the status of the coupon from Active to Redeemed. Or thirdly, via a third-party system your merchants can call into your site and redeem coupons over the phone through an automated system.