Priceline

Priceline is a travel booking website where users search and book flights, hotels, rental cars and vacation packages. It is known for letting travellers compare deals across providers and, historically, for letting customers name a price and be matched against travel offers, alongside standard search-and-book booking flows used across the industry.

Based in the United States, the site is used by travellers planning both individual trips and packaged vacations, from a single flight to a bundled hotel and car booking. Its ads.txt file lists 5 ad systems, all five selling its ad spots directly with none resold through resellers.