Book Review: “Contagious: Why Things Catch On”

If you read one book on marketing this year, make it Jonah Berger’s “Contagious: Why Things Catch On.” Published in 2013, this best-selling book is full of data-backed marketing advice that will be relevant for years.

Contagious Jonah Berger for blog

Author Jonah Berger is an associate professor of marketing at The Wharton School at the University of Pennsylvania, whose articles have been featured in many top-tier publications. His insatiable curiosity behind what makes advertising and marketing work is evident in this book and will keep you enthralled as well.

What Makes Online Content, Products and More Go Viral?

Why do some things catch on but others fail to gain any momentum or public response? Berger sought to find the answers to this question and then mapped out the reasons why in six principles or “STEPPS”:

  1. Social Currency
  2. Triggers
  3. Emotion
  4. Public
  5. Practical Value
  6. Stories

Chart of STEPPS

Each chapter of his book includes research and examples of how companies, organizations and individuals have applied the principles to help their products or ideas catch on.

Social Currency

This first principle is about making people feel good, making them feel valued–making them feel like an insider. The best blogs, the best products, the best stores and restaurants make their customers feel like they’re getting something special. Berger says, “Give people a way to make themselves look good while promoting your products and ideas along the way.” For example, people who drink Snapple love to share the little fun facts that are under each bottle cap. It can be as simple as that or more complex.


If your message is falling flat, maybe it’s not the message itself but a lack of a trigger. Rather than just focusing on whether your message is “catchy” enough, consider whether the message will be triggered by the everyday environment of your target audience. One story Berger shared was about the candy bar Kit Kat looking for a new way to boost sales and visibility. Pretty much everyone knows their catchy tune, “Give me a break, give me a break. Break me off a piece of that Kit Kat bar.” But sales had flattened out.  The Kit Kat team created a campaign that paired Kit Kat bars and coffee, describing the chocolate wafer bars as “a break’s best friend.”

By the end of the year, Berger cites, the brand had an eight percent lift in sales. Why did it work? Because so many people drink coffee regularly throughout the day that the coffee break was a frequent trigger which people could now associate with Kit Kat.

Go to the Book for More STEPPS

So now you have an idea of what’s included in the book. I don’t want to describe all six principles and give you a brief, more dry version of each. The stories Berger includes make this book well worth reading–more than once even.

A Compelling Read

Every business, every organization relies on word-of-mouth marketing in some way. Berger has done all the research for you and packaged the data in what is essentially a fun read as well as an informative one. He not only tells you why things work, but also why others don’t.

The stories he shares as examples within each one of the STEPPS are mostly built around products and services you’ve heard of, and even in the ones you haven’t heard of before, you’ll find yourself soaking them in and discovering ideas for your own products and services while you read.

Storytelling is such an overused word today, but Berger does a wonderful job of weaving the stories among the data so that you close this book wanting to go back and read it again.