Two years ago, I was a few credits shy of a free flight on Southwest and I was planning a trip to the west coast which usually runs around $300+. So, I did what ever resourceful consumer does, I signed up for a Southwest airlines branded credit card just so I could get the free credits and then canceled the next year. If you’re only a few credits (on airlines like Southwest and Airtran) or a few thousand miles (on traditional airlines) short of a free flight, you should consider signing up for that airline’s credit card in order to get enough free frequent flyer miles for that free domestic ticket. the best part about these credit cards are the fact that while they usually have an annual fee, they will waive it for the first year and likely waive it in subsequent years if you ask them to (i.e. have them waive it or you’ll cancel it).
Below I’ve compiled all of the airline credit cards I’m aware of, how many miles you need for a domestic (contiguous 48 states) and their current mileage promotions:
- Southwest Airlines Rewards Card  – $20 off your first purchase, 4 Rapid Rewards credits after your first purchase, 16 Rapid Rewards credits for a domestic ticket on Southwest Airlines.
- WorldPerks Visa Signature Card – 10,000 WorldPerks (Northwest Airlines) miles after your first purchase, 25,000 miles for a domestic ticket on Northwest Airlines.
- WorldPerks® Visa® Platinum Card – 10,000 WorldPerks (Northwest Airlines) miles after your first purchase, 25,000 miles for a domestic ticket.
- JetBlue Card from American Express  – 25 TrueBlue points with first purchase, 100 TrueBlue points for a domestic ticket.
- Airtran A+ Visa Signature  – 6 credits with your first purchase, 16 credits for a domestic ticket.