How Long Can Airline Bag Fees Carry On?

CHARLOTTE, N.C. -- Large airlines are reporting millions of dollars of new revenue from recently introduced bag-checking fees, but whether the practice can continue remains an open question.

While the fees have benefited the carriers where they've been implemented, two members of the group have been strongly opposed to the move. One is Southwest(LUV Quote), the world's biggest airline by passenger count. The other is Delta(DAL Quote), which is poised to become the largest carrier in terms of revenue passenger miles after it merges with Northwest(NWA Quote).

Perhaps the most telling comment on the charge was offered by Southwest CEO Gary Kelly during last week's earnings conference call. He said reservations agents tell him the first question they routinely hear from customers is, "Do you charge to check a bag?" ...