Hitwise published a report of travel website rankings in the U.S (pdf, 216kB). According to the report, the Top-20 sites get almost 50% of all visits to travel sites. And Top-100 sites get about two thirds of visits. Winner takes it all, eh?

Absolute visitor numbers are not estimated in the report, only relative values. Let’s see. TripAdvisor seems to have 0.89% market share. Other sources report that TripAdvisor gets about 25M monthly unique visitors. The size of online travel is huge.

In Hitwise’s categorization, map services are by far the most popular travel websites. Together MapQuest and GoogleMaps have a market share that is almost equal to the combined total of the rest of the Top-20. The Top-20 consists of map services, OTAs and airlines. An interesting tidbit is that TripAdvisor is the only social media / UGC site present on the list.

Based on visitor numbers, the biggest OTAs are:

1. Expedia (3.02% market share)
2. Travelocity (1.99%)
3. Orbitz (1.60%)
4. Priceline (1.53%)
5. CheapTickets (1.05%)

It would be interesting to see a similar report about top travel websites in Europe…