Your source for diet dog food
Suppose a seven ounce bag of dog food costs seven dollars. You find a dog food coupon online for a free three ounce bag of dog food. Perhaps you find a dog food coupon for one dollar off a seven ounce bag. Using that coupon at a store that is selling the dog food for five dollars and offers double coupons, you spend only three dollars. That is a small price to pay to try a new brand of dog food.