Some people are renting out a spare room, or maybe the whole house for a couple of weeks while they're away. Some people are buying properties purely to rent out via AirBnB, making use of a surprisingly large number of startups set up to provide guest screening, cleaning and welcoming services for AirBnB guests, and having it as one of their main income sources. Not only is it the latter group attracting the attention, it's also the latter group that's bending the definition of "hotel" to avoid being classified as one.