Bottom line: control and profits!! Today you pay VRBO 10% of your total revenue to send you bookings. In addition, with VRBO and AirBnB the guest pays up to a 20% premium on top of the owner,/manager retntal bill. On VRBO, a week long rental can cost the owner than the annual subscription on SLRBO. In addition, VRBO and AirBnB controls the communications with your customer and controls all of the funds involved in the transaction. Both of these organizations can arbitrarily decide that a guest deserves a refund without your input.
