Don't Fall Into the "Bonus Miles" Trap

Travelers who have accumulated frequent-flyer miles are finding it harder to cash them in, as rewards seats on popular routes are almost always full unless you book months or even a year in advance. Adding to the problem, airlines are cutting back on flights and increasing the number of blackout dates.

Despite these increasing hurdles, frequent-flyer programs continue to be popular with travelers. In their pursuit of free tickets, in fact, some travelers are willing to buy into an airline’s “bonus miles” promotion, which allows customers to double or even triple the number of miles earned on each flight. About 5 percent of US Airways passengers have chosen to pay to increase the miles they earn, while sales of bonus miles on AirTran are up 40 percent this year. With the exception of Continental Airlines and Southwest Airlines, every major domestic airline offers miles for sale to members of its frequent-flyer program.

Travel consultants caution that paying for those extra miles may not be worth the cost. Buying into the typical bonus-miles program will cost you about 3 cents per mile -- if you ever get lucky enough to use them, you’ll most likely get a “free” ticket worth about 1.5 cents a mile.

Despite the warnings, some travelers believe that paying for bonus miles is worth it. Although many airlines say that you can get a free ticket for as few as 20,000 miles, the reality is that getting your hands on a so-called restricted ticket has become virtually impossible because of lack of frequent-flyer seats. To qualify for an “unrestricted” free ticket, which will get you on just about any off-peak flight, you typically need at least 40,000 miles -- and that could make bonus miles the difference between getting a free ticket and not getting one.