Indeed, for many Airbnb hosts occupy their property at least part of the time. In fact, I think that's the niche it has filled best. There were already rental agencies (indeed, online ones!) to deal with permanent short-term rental properties. Airbnb offered a particularly hassle-free conduit for those who just want to rent their property out some of the time, such as folks who have multiple properties in various locations, occupy it seasonally, travel a lot for work, live abroad part-time, etc.