Maybe at some % of occupancy an AirBnB stops being spare space and becomes more hotel-like and needs to start collecting the same types of taxes, providing insurance, etc.
I'd be curious to see what % of Airbnb rentals are 100% occupied by the guests. I suspect that it's a majority of them, but I don't have any data to back that up with.
Isn't this effectively what, e.g., San Francisco is doing - once you rent out for X days, you face more burdensome requirements?