At what point does somebody giving me money in return for staying on my property turn my property into a hotel? I'm not talking the legal definition, I'm talking common sense.
The only working definition I can come up with is "when you reach a scale where the government can start taking a cut"
Back in the old days, that was a good-sized establishment. With computers, however, the government can go after anybody -- including lots of folks that earlier slipped through the cracks.