Hotels are a form of progressive taxation: rich out of town travelers pay more for housing than permanent residents. Generally travelers are richer than non travelers because traveling is usually a discretionary expense or paid for by a corporation.<p>AirBnb eliminates the progressive taxation, thereby raising living expenses for poorer residents. Rich people love it, poor people hate it. Sure, you can make some money in the short term by renting out your spare room, but in the long term, as rents rise, this process involuntarily turns your two bedroom apartment into a one bedroom + strangers' room apartment.<p>Just wait until San Francisco "Google bus activists" get a whiff of AirBnb.