Southwest Airlines, for example, only makes its fares available on its website. Delta Airlines last month told three sites—CheapOair, OneTravel and BookIt—that their services were no longer required. And American Airlines stopped using Orbitz on December 21st because of a contract dispute. Now American is also embroiled in a dispute with Expedia, which has suspended the sale of the airline's flights on its site (although they remain listed on Expedia's corporate travel site, Egencia).

The reason behind Expedia's decision is American's introduction of a ticket-selling system that requires agencies to link to its new "Direct Connect" platform, rather than use traditional distributors such as Amadeus and Sabre. American says Direct Connect will "help travel agencies help their own customers by giving them access to customized choices." But Expedia responds that American's new commercial strategy is "anti-consumer and anti-choice," and will result in "higher costs and reduced transparency for consumers, making it difficult to compare American's ticket prices and options with offerings by other airlines."

Under the new program, consumers who carry low account balances would be subject to a $9 monthly maintenance fee. Meanwhile, those with at least $50,000 in deposits and investments would receive priority customer service and higher interest rates on their savings. The new accounts will be tested in Arizona, Georgia and Massachusetts this month and are slated to be rolled out nationwide late this year or early next.