Kayak

Leading travel metasearch engine and major travel advertising platform within Booking Holdings portfolio

KAYAK is a travel metasearch engine founded in 2004 that revolutionized online travel shopping by aggregating search results from hundreds of travel sites to help users find and compare prices on flights, hotels, rental cars, cruises, and vacation packages. The platform processes billions of queries across its portfolio of brands and serves millions of travelers annually. While primarily known as a travel technology company, KAYAK operates significantly within the digital advertising ecosystem through its performance marketing model, generating revenue primarily through referral fees and advertising when users click through to partner sites to complete bookings. KAYAK was acquired by Booking Holdings (formerly The Priceline Group) in 2013 for approximately $1.8 billion and operates as a subsidiary alongside brands like Booking.com, Priceline, and Agoda. The company maintains a strong presence in the travel advertising space, serving as both a demand generator for travel suppliers and a monetization platform through its advertising products. KAYAK's technology stack includes sophisticated price prediction algorithms, flexible search tools, and mobile applications that have made it one of the most recognized brands in online travel. From an AdTech perspective, KAYAK functions as a high-intent traffic source and advertising platform within the travel vertical, offering sponsored placement opportunities for airlines, hotels, and online travel agencies. The platform's business model relies heavily on performance-based advertising, where travel suppliers bid for visibility and pay on a cost-per-click or cost-per-acquisition basis, making it a significant player in vertical-specific programmatic advertising and affiliate marketing.