Terms of the deal have not been disclosed but Kayak has purchased JaBo Software Vertrieb- und Entwicklung, which uses the Checkfelix as its trading name.

Checkfelix will continue to operate as a separate brand within the Kayak empire, but some management changes are expected to take place, with founder and ex-majority shareholder Hannes Jagerhofer becoming a marketing consultant to the business and John-Lee Saez staying in charge of operations but from Kayak’s European HQ in Zurich, Switzerland.

This is the second time in less than 12 months that Kayak has pounced on a strong player in an individual market in Europe.

German metasearch firm Swoodoo was bought by Kayak in May 2010, with CEO Christian Saller taking on the wider role of Kayak Europe managing director.

The deal for Checkfelix was completed on April 1, just a few months short of its sixth birthday, having launched in August 2005 and quickly becoming a significant player in Austria, covering search for flights, hotels and car hire.

Kayak is currently gearing up for its first foray into the public markets, having announced its intention to IPO in November 2010.

Kayak’s registration statements indicate that Kayak sold TravelPost on March 5, 2010, to The New Travelco for $3.6 million in cash and also received 800,000 shares of The New Travelco common stock.

The transaction was reported at the time, but the terms were unknown.

The New Travelco also assumed an unspecified amount of Kayak’s debt obligations, according to documents filed with the Securities and Exchange Commission in connection with Kayak’s proposed initial public offering.

Two Kayak board members, Joel Cutler of General Catalyst Partners, and Greg Slyngstad, who was TravelPost CEO until a shakeup in early January, are TravelPost stockholders.

The New Travelco later changed its name to TravelPost and purchased Web content, software, customer data, domain names and trademark applications from Kayak.

Kayak had acquired TravelPost in late 2007 as part of Kayak’s purchase of SideStep, which owned TravelPost at the time.

The New Travelco had raised $9.8 million in its initial funding round last year from 25 investors.

It isn’t known what percentage of TravelPost Kayak owns with its 800,000 shares.

As part of Kayak’s sale of TravelPost to The New Travelco, Kayak receives a monthly license fee of $50,000 for TravelPost’s right to display hotel reviews and other hotel-related information over three years.

Kayak’s registration documents also shed some light on Kayak’s purchase of German metasearch site Swoodoo on May 6, 2010.

Of the Swoodoo acquisition, Kayak explains: “In May 2010, in an effort to expand our European operations, we acquired all of the outstanding stated share capital of swoodoo in exchange for $9.5 million and 825,000 shares of our common stock. Upon the occurrence of certain events, including the closing of this offering, during the 30 business days following our giving notice of such event we will be obligated, at a holder’s request, to repurchase any or all of the shares owned by such holder at a price of €13.33 per share. As of September 30, 2010, we recorded a liability of $3.4 million with respect to these repurchase obligations.”

Kayak intends on running the two companies as separate entities but will “integrate technology best practices” between the pair over the coming months.

The deal sees Swoodoo chief executive Christian Saller take on the additional role of managing director for Kayak in Germany. The senior management team at Swoodoo will also take responsibility for both brands.

Kayak CEO Steve Hafner says:

“On many metrics, Swoodoo has been outperforming us in Germany. We’re glad to now have their team on our side of the table. This acquisition gives us a clear leadership position in Europe’s second largest online travel market.”

Deal rhetoric aside, Kayak’s move perhaps signifies that it is intends taking Europe seriously again after a low-key start in terms of traffic and the well known falling out and subsequent exit of its former European managing director Faisal Galaria.

Chief marketing officer Robert Birge says Europe is a “big focus” for the company and it will look to grow in markets elsewhere around the continent by either supporting its existing marketing efforts or through other acquisitions.

Ex-Skype executive Galaria was appointed as managing director for Kayak’s businesses outside the US in September 2008, but left under a cloud just nine months later in April 2009.

At the time it was understood that Galaria and other senior management in the US had disagreed over the strategy needed to build the Kayak business in Europe, a continent with challenges Hafner et al had not faced when creating the business in the US.

The Swoodoo deal is the first significant step on the acquisition trail for Kayak since it bought rival US metasearch site Sidestep in late-2007.

It recently offloaded the Travelpost user review site to the Expedia alumni startup NewTravelco.

But whereas the topic was rarely mentioned before, such was the determination by metasearch players to keep the model simple, it is now, by virtue of Kayak‘s move, getting some air time.

For example, Skyscanner and Swoodoo, both enjoying success in Europe in the metasearch sector, are far more philosophical about setting off such a seismic move to their existing businesses.

Take Skyscanner co-founder and chief executive Gareth Williams. He acknowledges the huge implications such a move by Kayak could have on the marketplace.

Is Skyscanner ruling it out?

Ask any metasearch player just two years ago if booking was an option they would consider and the answer would’ve been dismissed.

Not any more – Kayak appears to have changed many of its rivals’ thinking. Williams now says booking is “on the list” of things to do.

He quickly adds the caveat that the company needs “to get search right first”.

Christian Saller, CEO of Swoodoo, admits that booking is actually “something we discuss now all the time”.

So from fiercely defending the metasearch model for years (almost the reverse of Cheapflights and its proud defence of price comparison  until the launch of Zugu), in a short space of time the market has changed its thinking once again.