Contagious Why Things Catch On

Social Currency
and
ar e 
Triggered, Emotional, Public, Practically Valuable
, and wrapped into 
Stories.
Each chapter
focuses on one of these principles. These chapters bring together research and examples to show the
science behind each principle and how individuals, companies, and organizations have applied the
principles to help their products, ideas, and behaviors catch on.
These principles can be compacted into an acronym. Taken together they spell STEPPS. Think of
the principles as the six STEPPS to crafting contagious content. These ingredients lead ideas to get
talked about and succeed. People talked about the hundred-dollar cheesesteak at Barclay Prime
because it gave them 
Social Currency
, was 
Triggered
(high frequency of cheesesteaks in
Philadelphia), 
Emotional
(very surprising), 
Practically Valuable
(useful information about high-
quality steakhouse), and wrapped in a 
Story.
Enhancing these components in messages, products, or
ideas will make them more likely to spread and become popular. I hope that ordering the principles
this way will make them easier to remember and use.
**
The book is designed with two (overlapping) audiences in mind. You may have always wondered
why people gossip, why online content goes viral, why rumors spread, or why everyone always
seems to talk about certain topics around the water cooler. Talking and sharing are some of our most
fundamental behaviors. These actions connect us, shape us, and make us human. This book sheds light
on the underlying psychological and sociological processes behind the science of social transmission.
This book is also designed for people who want their products, ideas, and behaviors to spread.
Across industries, companies big and small want their products to become popular. The
neighborhood coffee shop wants more customers, lawyers want more clients, movie theaters want
more patrons, and bloggers want more views and shares. Nonprofits, policy makers, scientists,
politicians, and many other constituencies also have “products” or ideas that they want to catch on.
Museums want more visitors, dog shelters want more adoptions, and conservationists want more
people to rally against deforestation.
Whether you’re a manager at a big company, a small business owner trying to boost awareness, a
politician running for office, or a health official trying to get the word out, this book will help you
understand how to make your products and ideas more contagious. It provides a framework and a set
of specific, actionable techniques for helping information spread—for engineering stories, messages,
advertisements, and information so that people will share them. Regardless of whether those people
have ten friends or ten thousand. And regardless of whether they are talkative and persuasive or quiet
and shy.
This book provides cutting-edge science about how word of mouth and social transmission work.
And how you can leverage them to make your products and ideas succeed.
*
When I use the word “viral” in this book, I mean something that is more likely to spread from one person to another. The analogy to

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diseases is a good one, but only up to a point. Diseases also spread from person to person, but one key difference is the expected length
of the transmission chain. One person can easily be the initiator of a disease that spreads to a few people, and then from them to a few
more people, and so on, until a large number of people have been infected, solely due to that initial individual. Such long chains, however,
may be less common with products and ideas (Goel, Watts, and Goldstein 2012). People often share products and ideas with others, but
the likelihood that one person generates an extremely long chain may be small. So when I say that doing X will make an idea more viral,
for example, I mean that it will be more likely to spread from one person to another, regardless of whether it eventually generates a long
chain or “infects” an entire population.
**
Note, however, that the recipe analogy breaks down in one respect. The principles are unlike a recipe because not all six ingredients
are required to make a product or idea contagious. Sure, the more the better, but it’s not as though a product that is Public will fail
because it’s not wrapped in a Story. So think of these principles less like a recipe and more like tasty salad toppings. Cobb salads, for
example, often come with chicken, tomato, bacon, egg, avocado, and cheese. But a salad with just cheese and bacon is still delicious. The
principles are relatively independent, so you can pick and choose whichever ones you want to apply.
Some of the principles are easier to apply to certain types of ideas or initiatives. Nonprofits usually have a good sense of how to
evoke Emotion, and it’s often easier to play up Public visibility for products or behaviors that have a physical component. That said,
contagious content often comes from applying principles that originally might have seemed unlikely. Heavy-duty blenders already have
Practical Value, but