In the past there were few airline that offered a credit card. There are now two major airline cards: Continental Airline World MasterCard and United Airlines Mileage Plus card. These two leaders of the airline industry started the frequent travelers credit card option.
It was a partnership between airlines and credit card companies that started this way of life and now there are as many cards as there are airlines. They are all pretty similar as you can earn miles by using the card. If you obtain a generic credit card, one that is not tied to one airline, you have much more freedom in your choice of airline to fly. This way you are not limited to a certain airport or times that don’t fit with your plans.
Other perks can be sign up bonuses and earned miles from rental car, hotels and cruises. Some cards offer 5,000 bonus miles after using the card just one time. Read the small print to find out just how many miles it takes to get that free ride.