There is a great market today for Airline Miles credit cards, so how can you make sense between all those offers ? Read the following point and you might be able to develop a winning strategy

• Ask more than one dollar per mile.
  Anyone who is still earning only one mile per dollar or collecting points on only one airline should rethink his or her cards.
• Consider the Starwood Preferred Guest American Express Card
  For every 20,000 points you redeem, Starwood gives you an extra 5,000 points for free, which means you’re really receiving 1.25 miles per dollar spent. You can redeem them on 30 airlines, including every major U.S. carrier, and you need never stay at a Starwood hotel to reap these benefits. Be aware that it can take weeks to exchange points for miles on the airline you select, so the program isn’t great for last-minute tickets. Otherwise, the Starwood card is one of the most powerful ways to earn miles. What’s more, you pay no fee the first year and only $30 annually thereafter.
• Consider the Gold Delta SkyMiles® Credit Card American Express
  Like some other airline-branded cards, it awards double miles on certain purchases—such as when you use it at supermarkets, gas stations, and home-improvement stores. Additionally, the card ran a promotion awarding double miles on every purchase last November and December. If Delta miles are hard to redeem, you can use them on alliance partners Continental and Northwest. Remember however that to rake the largest gain you have to use it only for purchases that award double miles.
• Consider a card that gives you “elite-qualifying miles”
  If your priority is to keep or achieve elite status, which provides perks such as express check-in and early boarding. Ordinarily you must fly 25,000 miles annually on one airline to earn elite status. If you’re short a few thousand miles, you can get the boost you need from a card that provides elite-qualifying miles.
• Don’t stop collecting miles on your preferred airline just because it is in bankruptcy.
  
  From 1991 through 2005, no one with a frequent-flier program was ever harmed by the bankruptcy of a major carrier. On the contrary, troubled airlines often sweeten the deal for frequent fliers to make sure they don’t flee. Soon after Delta declared bankruptcy, for example, it offered double miles for every purchase made with a Delta AmEx.
  .
• Beware credit cards offering airline miles that aren’t really airline miles.
  
  Fly any airline, anytime—no blackout dates or seat restrictions,” promises the no-fee Capital One Visa. Sounds great, until you learn that the number of miles needed for a free ticket varies based on the cost of the flight. A $500 domestic ticket, for instance, would require 40,000 miles rather than the typical 25,000. Another problem with Capital One miles: You can’t use them for upgrades or pool them with the miles you get through airline programs, and you must redeem them at least 21 days before the flight. “The marketers call them airline miles,” says Petersen, “but they’re not.”
• Consider the Platinum Delta SkyMiles® Credit Card American Express or United Mileage Plus Platinum Class Signature Visa
  Choose one of these two cards if your priority is upgrades. It’s getting harder to obtain upgrades through elite status, so you are better off racking up points on these cards.For more information on this subject you can refer to
  The Perrin Report