The worst thing is, that when you accept AirBnB booking, or an other
booking, and you don't immidiately close your listing on Booking.com
and get another booking. You will have to pay the 13% fee.
Disclaimer: We are company that prevents double-bookings. Our users manage both Airbnb and bookings.com from our site hostaway.com. I'd like to share some insight from the hundreds of properties our customers have.
Booking.com and Airbnb come from two entirely different worlds. Airbnb was created for home sharing while booking.com was created for hotels. Many bnb owners have problems when expanding business to Airbnb while many Airbnb hosts face challenges when expanding to booking.com
Booking.com acts as a booking agent. It's a 1-sided marketplace where they sell rooms. It's important to understand the difference. The hosts set up the rates and availability and are responsible for ensuring they are correct. Guest bookings are automatically confirmed for the host. Typically the host is responsible for providing the guest with arrival information and a payment method. The host is not able to cancel a booking. Once the guest has arrived, the host pays booking.com a commission.
Most of the issues people have are related to the different business models the platforms provide. Booking.com charges only for successful bookings. On booking.com, the customer is king: if you sell a room at a certain rate, the guest should get it. On Airbnb, which is a 2-sided market place, there is no specifc customer. Instead, each reservation is a result of (sometimes automated) negotiations. This gives more flexibility for the host, but many guests that are new users may end up getting rejected because of lacking communication skills.
In some markets, booking.com rates are much higher than airbnb and hosts get a good amount of bookings. We have clients that receive more than 50% of their bookings from booking.com. There are also markets where you don't really get premium-priced bookings on booking.com, but the best way to find out is to try it.