I will leave a buck or two, depending on the size, complexity of bathroom and level of service - or sometimes, with lousy service, nothing - per day, on the bathroom counter near the sink. And I do not wait until the bitter end, because I notice that if I start after the first overnight, my level of service usually goes up. The folks don't get much credit or respect, or money either. I tend to tip and to say a few nice words and smile...

Guess how much I left in the Hampton Inn NY - JFK? The one with the CSI-level "biologicals", at least a couple of strains of mold, and human hair from several donor sources (well, I think it was human!) in the bathtub enclosure? As we say in Mexico, the correct asnwer is bupkis. Well, not real bupkis (goat, er, feces,) but in the contemporary American meaning of the word... if it had been excremento de chivo, it might have gotten lost among the rest of the grunge.