Scarcity is one of the most powerful motivators in consumer behavior. When something is limited, rare, or exclusive, our brains light up with desire. Behavioral scientists call it reactance theory : we don’t just want the thing—we want it more when we think it might disappear.

Social proof shows up in every aspect of our behavior and decisions. What other people say, think and do are powerful motivators.

Have you ever walked into Costco planning to buy just one or two things and walked out with a cart full of stuff you don't need?