Contagious: Why Things Catch On

Berger challenges conventional wisdom about what makes products and ideas spread. The central argument proposes that while interesting or novel items may generate initial excitement, environmental triggers play a more crucial role in sustaining long-term discussion and adoption.

Berger opens with a comparative analysis between Walt Disney World and Honey Nut Cheerios. Despite Disney World generating more excitement and emotional connection, research indicates that people discuss Cheerios more frequently. This counterintuitive finding leads to an examination of how environmental cues influence human behavior and conversation.

Berger introduces BzzAgent, a word-of-mouth marketing company, to demonstrate how products naturally enter everyday conversation. The company’s founder, Dave Balter, established a network of voluntary participants who try products and share genuine opinions. Through analyzing hundreds of BzzAgent campaigns, Berger and his colleagues discovered that a product’s level of interest did not correlate with sustained discussion. This finding contradicted prevailing marketing theories about generating buzz through novelty or surprise.

The research distinguishes between immediate and ongoing word of mouth. Products that intrigue people may receive initial attention but fail to maintain long-term discussion. The key factor determining sustained conversation is the presence of environmental triggers—external cues that remind people about products or ideas.

To support his argument about triggers’ influence, Berger presents several case studies.