I went to the feed store last week to pick up a 50 pound bag of shelled sunflower seeds. They had me take a slip around to the back to the drive-thru so a guy could place it in my car.
Right there where I parked, was a bushel basket with a sign on it that said...
"Tips welcomed. Thanks."
The guy did a real good job of placing that bag in the passenger seat. But, alas, I did not tip him.