I wouldn't get a miles card, because they usually have annual fees and because it doesn't really seem worth it to do frequent flier miles. You've got to accumulate a lot of them to get somewhere, and in the meantime you're always picking a particular airline for all of your trips, and it's not likely to be the best fare to where you're going. It's probably worthwhile if you charge a lot of stuff though - maybe look into what the fee is, how many miles you would get in an average month of spending, and how many miles that airline requires for a trip.