13%. That is the share of airlines' online passenger revenue that flows through OTAs, according to Phocuswright estimates, even as OTA bookings overall rose 4% in 2025 and their share of U.S. travel spending keeps climbing. The steady headline number hides an uneven one: airlines have largely reclaimed the online air customer, and hotels are doing most of the work behind the OTA growth story. Read the full breakdown of what that concentration means if hotel growth cools.