I used to chase the gas discounts with cards. Then we switched to a (was Continental Airlines -now United) Visa card. We use it for everything; pay it off monthly, then enjoy the airline miles. Earlier this year, we went to Rome for 10 days and used airline mileage points for air and hotel. We still have more than enough miles for another trip abroad. I just don't think chasing a few cents off a gallon is worth it versus enjoying the travel opportunities with the airline miles. United also has a catalog for spending your miles. I have enough miles now for a new Apple laptop.