LOL, just hope that one morning the cash register freaks out and they can't get it to charge your card and it's a workday and they're in a hurry to get people in and out.
True story. It's happened to me twice, when I've ordered $20 worth of stuff. 🙄
But seriously, don't cheat them out of money. Coupons are not for everyday use, they're just promotions.