Software that allows:
1) Targeting grocery coupons to users based on pre defined criteria
2) User sees coupons on website / mobile / facebook page and clicks coupons she wants to redeem.
3) Clicked coupons get stored in user's online account, which is linked to either store loyalty card or telephone number
4) User goes and buys some products in a grocery store. At checkout, she identifies herself by scanning her store loyalty card or entering her telephone number. If she had a coupon for any item, she gets a discount automatically. Discounts can either be calculated and applied in (i) real-time so that user's bill gets reduced, (ii) end of day after getting the transaction files from the retailer
5) Admin Modules at the back end to control all of this process and generate reports
6) Security mechanisms to prevent fraud, and control coupon issue limits, campaign budgets etc.
Software architecture should be designed so that it can handle multiple transactions in real time, and is scalable so that as transaction volume increases, software can cope up.
For example, see following sites: [url removed, login to view], [url removed, login to view], [url removed, login to view]