Trivago, Kayak, etc would say otherwise. Yes margins are slim, but this is a classic case of why no UI/UX will ever trump mass distribution. OTAs are basically the walmart of the digital world.
Trivago is in the hotel business, which has better margins. Some sites like Expedia will actually take a loss on a flight if you book it with a hotel or rental car, which they make a profit on.
Kayak (and the rest of the Priceline/Booking.com group) takes a much more advertising driven model. You'll notice the site has lots of pushes to sign you up for their various mailing lists that yield long term reoccurring revenue on airline credit cards and travel packages.
It's odd to see so many commenters insist that there's money to be made in flight search, despite not having industry experience.
This comment nail it dead-on. Flights are a loss leader. It's the gateway to more profitable travel services like booking hotels, which ironically have shrinking margins over the last few years.
There's no need for an OTA middleman when a hotel can build a direct relationship with the customer (via loyalty programs).
Trivago, Kayak, etc would say otherwise. Yes margins are slim, but this is a classic case of why no UI/UX will ever trump mass distribution. OTAs are basically the walmart of the digital world.