By distancing itself from third-party sites, JetBlue can avoid the transaction fees imposed by the online travel agents. (Ramon Espinosa/AP)

Southwest has avoided online travel agents from the start. Delta started to back away from third-party booking sites a few years ago. Now, JetBlue is the latest airline to clip ties.

As part of its "new online distribution strategy," JetBlue will no longer allow a dozen sites to list its flight information or sell its tickets. The carrier has parted ways with SmartFares, MyFlightSearch, VacationExpress, FlyFar.ca, FlightNetwork, Vayama, WhatsCheaper, Vegas.com, JetsetVacations, CheapFlightsFares, QuickTravels and kiwi.com. The airline will continue to work with the larger entities, such as Kayak, Google Flights and Hipmunk. The decision helps push the company closer to its ultimate goal: to entice travelers to book on its site.

"Many customers mistakenly believe they can find lower fares on third-party sites," said JetBlue spokesman Morgan Johnston, "but JetBlue has long guaranteed customers that they will always find the lowest fare on jetblue.com."

Johnston said the dozen sites represent a small percentage of the airline's bookings and that the majority of its customers purchase their flights through the airline. By distancing itself from third-party sites, JetBlue can avoid the transaction fees imposed by the online travel agents. It also has more opportunities to drum up revenue with such online extras as travel insurance, credit card offers and vacation packages.

Booking with the carrier benefits the traveler, too. Members of the TrueBlue frequent-flier program earn bonus points, and any customer who discovers a lower fare elsewhere on the day of booking receives a $100 credit. When searching for a flight on JetBlue, travelers can see all of the fare categories, including the subgroups of economy class. They can also discover sales available only on the site. By comparison, third-party companies typically list only one fare type and do not promote sales.

But the overall trend of inching away from these sites has its downsides. George Hobica, founder and president of Airfarewatchdog.com, said third-party sites sometimes post cheaper fares. He recently found a significantly lower price to South Africa on Orbitz and to Rome on Expedia. The fares on KLM and Alitalia, respectively, were about $200 more. Third-party sites also allow travelers to create more flexible itineraries with a patchwork of airlines for one trip — for example, flying out on American and returning on JetBlue. (Kayak calls them Hacker Fares.) The omission of certain airlines on booking sites also constricts travelers' research capabilities.

"If it spreads," Hobica said, "it will be much harder for consumers to fare compare."

For now, Johnston said the company is focusing on a "much smaller number of OTAs that can deliver value for JetBlue and our customers." Hobica, meanwhile, said that according to an industry insider, Delta could pull the plug on the larger sites, following the contrails of Southwest.

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