Small discounts feel pointless, which is why uncertainty often outperforms them. A new set of experiments caught my attention because the pattern was so consistent. When the discount is tiny, buyers mentally round it down to ZERO. They treat it like lint on a sweater. (At best.) A small guaranteed discount rarely feels worth acting on. It can feel like an insult. But give them a chance at something bigger and everything changes. The research shows that a 10 percent chance at a free night was...