Airbnb is a model that allows you to earn money without owning any property. It allows you as an investor to list a property at a higher price than the one you rented it with from the landlord, and hence you repay the balance after paying the rent. It is entirely legal to operate this way; all you need is to communicate your intentions to the property owners. Sometimes you may come along a landlord who is not open to it, and other times you get those that are open to it. Just approach it honestly and get the right property owner for your business strategy.
Airbnb without Owning was founded to help people list lodgings worldwide. It requires you to set up a business foundation, and this is determined by the number of properties you want to list. Set a legal entity that will help you get good deals with the property owners.