Social proof refers to a psychological phenomenon in which people seek direction from those around them to determine how they should act or think in a given situation. It’s like when you see a long line outside a nightclub and assume that the club is good because it’s in such high demand. Social proof can be identified in social media by the number of interactions a piece of content receives or the number of followers you have. The idea is that if others share something or follow someone, it must be good.
A person sees a restaurant with a long line outside and assumes it must be good because others are waiting to dine there. This assumption is based on social proof—the belief that the crowd’s behavior indicates the restaurant’s quality.