Booking, the other way round. A traveller drops a pin and sets a radius, the dates, the guests and the price they want to pay per night. The request reaches every place in range with a free room that fits. Each place answers on its own: accept the price, offer another, or decline. The traveller books the offer they want.
For hosts: fill nights that would otherwise stay empty, at a price agreed per request, without changing your published rates.