I disagree with those who say ff programs don't matter to the occasional traveler. With the explosion of bonuses for affinity credit cards (e.g. Chase UA Mileage Plus, Southwest), you can get enough points for a couple of free domestic tickets just for getting the card and a minor amount of spending. In addition, just having the card gets you perks (free baggage check, priority boarding) and you accumulate more mileage just by using the card.