You gotta keep looking! My hotspot? A machine where the users are always in a rush and barely take time to look - the downtown CVS! I can sit in the parking lot and about every 5-20 minutes, someone is using it. The workers can't check it easily either, which is a plus, and most times when I introduce myself to customers (or help them because they can't speak English well) I always explain their finds in the reject tray to them (when they notice the coins dropping down). The machine users usually let me keep neat stuff about 90% of the time, but I don't press them if they say "I'd like to keep this one".