I generally use miles earning cards (SPG first, then UA), but on gas purchases, I use cash back cards from Shell & Exxon/Mobil. AAA & Chase both have 5% gas cash back cards. All the offers I get for cash back cards only have a 1% cash back, so I'd rather earn the SPG points or miles over the 1%. I spend about a total of 1,000/month on my credit cards, so i'd rather have the 1000 miles/points than the 10 bucks back, not a great valuation, but its an easy way to get miles. That combined with long distance offers & other promos, has helped out a lot. I also don't pay annual fees in general unless the sign-up bonus is amazing. I did that with DL and got 25K for 85.00 and with UA I got 20K for 60.00 and SPG i got my first year free, but I think I'll probably continue with it, but haven't decided as yet. I also keep my BA visa account active so it keeps my BA airline miles account active (same with SPG - I don't stay too often with them, and if a year goes by, my SPG Amex takes care of my points expiring - to which there has been discussion on FT, it's useful for that, in my opinion...)