[smueller1234]

That's incorrect. It's never been as high as 20%. That's a claim that I've seen frequently over the years on HN, but it was never the case, at least at Booking.com.

They have a few mechanisms to try and drive up commission from the usual 12%, though. They have a preferred program which boosts search results but costs 3%> They would have loved to drop it to better tune search, but they were addicted to the incremental revenue.

At various times there were also dynamic ranking boost efforts, where a hotel could increase boost their ranking (with a preview) by increasing the commission percentage. IIRC that went as high as 18%.

Both of those applied to the default search results order ONLY. If you clicked "order by price" or similar then you simply got that.

(Worked for booking until end of 2017.)