You’re going about your daily business, perhaps on a walk through your neighborhood. During this walk, you come across two children at a lemonade stand. “Lemonade $0.50” The signage says. Not the price you paid in years past, but you’ve worked up a thirst. You ask to buy a cup from the children. They reply “For $5 you get a special cup that will give you 50% off our lemonade all summer.