Two years ago, Kayak began taking direct hotel bookings through a white-label partnership with the Travelocity Partner Network.
It marked a sharp turn for the metasearch site, which had previously only referred visitors elsewhere for booking.
Now a user could create an account on kayak.com and use the payment information stored in it to complete a booking as if Kayak itself was handling the transaction.
The company has since added numerous "direct" booking partners including Expedia Affiliate Network.
In March 2012, Kayak added direct bookings of flights, starting with Air Canada.
In July 2012, Kayak added a third-party, white-label booking program for car rental reservations with Advantage, Avis, Budget, and Hertz.
The company is in the process of adding the option to book cars "directly" all product types across its international websites.
Will Priceline eat these deals up?
You may be wondering how will these relationships be affected by the company's acquisition by Priceline, announced last November.
The official word is not to worry. Priceline won't demand its share of these white-label deals or try to cut off
Priceline reminded us that it is on the record stating:

Kayak's current management team will continue to manage Kayak's operations independently as part of the Priceline Group of companies.
We asked Robert Birge, chief marketing officer at Kayak for his view. Birge said by e-mail:

Comprehensiveness and choice is Kayak's value proposition to users so, I can't imagine why anyone would conceive a notion to change that.
We don't ever comment on terms of our business relationships, so I'm afraid I can't speak to that.
I believe each of our partners in this space would tell you that we have created a positive partnership in this effort.
In its favor, Priceline has a habit of acquiring companies such as Agoda and Booking.com and resisting the temptation to disrupt the entrepreneurial structure in place at its takeover target.
So the white-label deals are safe for now.