How a airline credit cards works is for every dollar you spend your credit card company gives you a mile towards your next plane ticket. Some companies give you a dollar for that mile but most stay with the actual distance. Most airlines have a credit card where you can earn air miles. Because of a recent merger the Delta Sky Miles Credit Card has been a must have for any Delta passenger.
Many people will rack up the miles over a couple years and use them to go on a big vacation. Some airlines though have started to not tell you what their black out dates are and instead will tell you that the flight is full. The airlines would rather charge full price for a seat on a plane leaving on a Saturday instead of you taking that seat for free. The airline will do their best to get you on off day flight at a weird hour where the flight is not full instead. They know that they are going to have seats available so you are forced to use these times. If you are flexible then it does not really matter because you are getting a free ticket.
Should you apply for an airlines card or go through a bank? These comes back to how much you plan on traveling. If you can be flexible then go with the airline. You must remember that some airlines only fly to certain locations. What if you want to go to South America and your airline does not go there. Then you are stuck with unused miles. Unfortunately, many people find this out the hard way. They call up their credit card customer service and are told it while they have started planning the trip out.
The best bet would be to apply with a bank. They will give you miles that can be used on any airline with no blackout dates. You get the most flexibility this way. No getting up at 5 am on a Tuesday to make it for your early flight just because the airline told you this was the only time. The banks will want to keep your business and will be able to provide better customer service also. One of the best bank cards is the Citi Premier Pass Credit Card. Take the time to see what type of card makes the most sense for your situation. This way you can plan where and when you want to go instead of being told when you are going to go.