I have only recent direct experience (OTAs all being 10-12%), but I do know one recent change is that “AirBnB model” listings are turning up on Booking.com a lot more now (renting out your holiday home as if it were a hotel with one unit). I know AirBnB charges 20% commission (I think they call it a service fee), perhaps for these cases Booking.com is offering those operators 20% as well.
Ah, that would explain, thank you. No way they would have been able to make that change on hotels.
That makes perfect sense, they were the same type of single villa style. The biggest things I discovered is that while airbnb charges the host 3-4%, they charge the guest 9-15%. Booking.com reverses this and charges the guest no fees while the host has all the cost, 20% and the most risk if the charge/credit card was fraudulent.