#56 Couponing For Coffee
The best loophole I found was a couple years ago when the Dunkin Donuts app first came out. After you amassed 200 points (which is about $40 worth), you received a coupon on the app for a free coffee. What they didn’t account for was that you could screenshot the coupon and use it over and over again. I used it for at least four months before they fixed the system. I must’ve gotten hundreds of free coffees.
Credit: Ner1878