Can I stop my competitor from accepting my coupons?

I don't know of any way of stopping someone else from redeeming your coupons without getting tricky and complicated with the coupons or the method of delivery. I guess you could use some technology to only deliver the coupons through a special smartphone/ipad application that only allows the coupons to be seen when the GPS sees that the device is in your store. That probably defeats the purpose of the coupon though, since it is intended to bring them to your store and with this system they can't see it until they are already there.