Coupon for one gallon of gas

"I didn't realize it, but these coupons are good for one gallon of gas at all gas stations. You probably have one or two just lying around somewhere, now is the time to use them before they lose their value, and it's too late!"
 http://directorblue.blogspot.com/2012/04/coupon-for-one-gallon-of-gas.html