A buddy of mine worked at BurgerVille for a couple years.  Oh the stories he would tell me.  A person once got upset about the Jars(not little cups) of special sauce costing money.  They were meant to be taken home and put in the fridge.  Nobody wants to sit at a restaurant and watch you dip several orders of large fries into a jar.  Of course eating a jar of Mayo was ok because they had a diet Coke.