Unsurprisingly, using residentially-zoned space for commercial purposes is profitable. Don't most full-time bed-and-breakfasts have to get licensed? (I'm assuming that making $4,500/month implies being nearly full-time; maybe I'm wrong.)<p>To me, this seems fine when rare. So let's say I rent out a room once a month or something along those lines - no big deal. If I'm treating it like a real b-n-b, though, it seems like I'm engaged in some real commerce that is probably regulated. Presumably Airbnb behaves agnostically on this issue, allowing the responsibility to fall to the property owner?<p>I'm delighted for the specific homeowners being discussed here, but concerned about the general case.