In most hotels I visit these days, I can see a sign like the one in the picture, with basically the same message: if you want to keep the same towel for multiple days, hang it up, if you put the towels on the floor, the hotel staff will replace them.
I always hang up my towels, very often not so much because I think of that program, but mostly because hanging up is what you do with towels. Here is what I observed: even if I hang out my towels reasonably neatly, they get replaced nonetheless.
From what I have read online, participation into these environmental programs is low (less than 25%) and the only way to make people participate is to not mention the environment, but to tell people that everybody else is doing it.
It is very difficult for me to connect my experience with these numbers. First I don’t know if my observations are just anecdotical counter-examples, or that the hotel staff is so efficient at folding back the towels to fool me, so I don’t know in which bucket I fall. Second, the fact that social norms is a more powerful motivator than just plain common sense, or an appeal to the preserve the environment is a bit depressing and certainly does not resonate with me.
I understand that herd mentality is a powerful force, but invoking it in hotel is a bit weird: the nature of the place means that either the place, or the patrons will be pretty alien to me…