During a recent stay at the Disney Swan hotel in Florida, I confess I did something in the bathroom I have done many times before. I used too many towels and carelessly left them on the floor. It’s not something I’ve thought much about before: I leave the hotel and who’s to know? But something struck me as I walked out the door. I would never do this as a guest staying in a place on Airbnb. I behave differently because of the reputation system in place that means not only do I rate hosts, but they rate me. Trust lies intimately between the perceptions of the two users.