However, with the acquisition of Kayak, it marks its entry in the meta-search space.

FORBES: How Can Kayak's Acquisition Fuel Priceline's Growth?

Priceline recently announced its acquisition of Kayak, a leading travel search company, which marks its entry into the meta-search space.

FORBES: Breaking Down Priceline's Business And Stock Drivers

Even if rival travel agencies terminate meta-search contracts with the Norwalk, Conn.

FORBES: Connect

Meta-search remains an integral part of the online travel booking supply chain.

FORBES: How Can Kayak's Acquisition Fuel Priceline's Growth?

The newest player in the flight-and-hotel meta-search market is Hipmunk, a site aimed at de-cluttering travel search results and ranking results by levels of "agony".

BBC: The future of travel search

Think again: Expedia ( EXPE) exited the meta-search market, spinning off TripAdvisor ( TRIP) in an IPO last year, when Priceline and Orbitz ( OWW) balked at disclosing advertising budgets to Expedia.

FORBES: Connect

And meta-search sites like Kayak and Sidestep try to earn a buck helping you find the cheapest among all of the above, plus the sites of airlines, hotels and car rental companies.

FORBES: Priceline Is Not Cheap But May Still Be A Bargain

Between finding a hotel, flight, rental car, cruise, train or tour, savvy travellers use any number of tools, from online travel agencies like Expedia to meta-search websites like Kayak, to fit all the pieces of the puzzle together.

BBC: The future of travel search

Kayak, a so-called meta search engine for the travel industry, has come out of nowhere and grabbed market share from the big online agencies.

FORBES: Travel Web Sites Get Personal