Pretty clear that mostly what SF cares about is the tax revenue. That is the only part that is centralized and Airbnb has to provide. Everything else is self reported by the hosts which means that maybe the city will lean on them if the neighbors or landlords complain. Pretty smart of Airbnb to pay off the city and avoid responsibility for anything else. This is definitely a scalable business model if they can get other cities to buy into the same idea.