Contagious

The science behind why some ideas spread and others do not. Jonah Berger, a marketing professor at Wharton, spent years studying what makes content go viral, products get recommended, and ideas stick in people’s minds. Contagious distills that research into six principles that explain why things catch on.

Why Start Here

Berger has written three books, each exploring a different aspect of social influence. Contagious came first and remains his most widely read and practically useful work. The STEPPS framework (Social Currency, Triggers, Emotion, Public, Practical Value, Stories) gives you a clear mental model for evaluating whether your product, idea, or content has the ingredients to spread organically.

What makes Contagious stand out among Berger’s books is its directness. Every chapter gives you a principle you can apply immediately. Invisible Influence and The Catalyst are both valuable, but they explore subtler aspects of human behavior. Contagious tackles the question most marketers and entrepreneurs ask first: how do I get people to talk about what I am building?

What to Expect

A fast, engaging read at 244 pages. Berger writes with the clarity of a great teacher, weaving academic research into stories that stick. Each chapter covers one STEPPS principle with examples ranging from viral videos to restaurant design to public health campaigns. The book is accessible to complete beginners while still offering insights for experienced marketers.