I used to think guesthouses only existed on grand estates. They were the kind of thing I'd see in a teen comedy and wonder how these kids got to have another house next to their house, solely for the purpose of partying. Now, it seems, they are a badge of ambitious entrepreneurship ( thanks, Airbnb! ) and maybe even a thing regular people can put together in their regular backyards. At least that's what this listing on Amazon would have us believe.