I do this at my local chain, Giant Eagle, all the time. In my case, I get 10 cents off per gallon of gas when I buy $50 in gift cards, which I than use for eating out or whatever. At times you also get double miles for spending at grocery stores, and than turn around and buy your discounted gas on the card for even more Skymiles. I don't see why it would not work for your situation as well. At my chain, they have Sears, Home Depot, and other retailer cards as well, so if you have a major appliance purchase or home remodeling to do, use the card and buy gift cards for your purchases. A recent example was where iRobot was offering a free Dirt Dog robotic cleaner if you purchased a Roomba Robotic vacuum at Bed, Bath, and Beyond(BB&B). I went over to the grocery store and bought $250 in BB&B gift cards, received the 50 cent per gallon discount on gas, received 500 Skymiles for the purchase, and recieved my free robot.