This is something we'll keep an eye on as we accumulate more miles.

There are other ways to accumulate miles.

It's not uncommon to accumulate enough miles for an award ticket without ever flying with an airline.

How knowledgeable are you when it comes to accumulating such miles?

Its publications tell you about promotions and give tips on accumulating miles.

Customers accumulated miles from flight segments they fly or through Continental Airlines partners.

"People are accumulating miles for the sake of not flying coach," he said.

Just look at the popularity of frequent-flier programs and the airline-linked credit cards, which accumulate free miles.

The program is expected to generate an additional $100 million in annual revenue for the airline, as United passengers try to accumulate miles.

Once a customer accumulates enough miles, the big three offer a much greater variety of trips in this country and abroad than other airlines.