I find that grocery coupons are a great way to save money, especially since all the stores near me offer double coupons. In clipping, every once in a while I come across a coupon that specifically states "do not double." Now, it is my understanding that a double-coupon policy is set by each individual store/chain and that regardless of whether they take the coupon at face value or double value, all they are reimbursed by the manufacturer is the standard face value plus 8 cents. So, a store that offers double coupons does not get a double reimbursement, they get just the standard face + 8 cents and the "double" value is eaten by the store as a marketing expense. So, why do some products have coupons that say "do not double"? If my understanding is correct, it should not matter one whit to the manufacturer whether the customer gets $1 off or $2 off, since they will only have to reimburse the store for $1.08. Why do they care if a store wants to offer an additional discount?