If you always travel with the same airline, that might be the way to go because you usually get additional perks in addition to miles, like early boarding, club passes, etc. We always fly US Airways to Jamaica, so I went with a US Airways World Mastercard and use it to buy things I normally buy so I pay it off every month and never carry a balance. I figure the annual fee in to my Jamaica expenses, so I just see it as getting really cheap flights by the time I pay the taxes and fees.