CONTAGIOUS
BUSINESS ENGLISH
SUMMARY
This book is perfect for anyone who wants to learn more about how to spread ideas, increase brand
awareness, or grow their customer base. In it, Wharton marketing professor Jonah Berger explains
what makes certain ideas, products, and stories popular. He explains 6 mechanisms that contribute
to virality: social currency, triggers, emotion, practical value, public, and stories.
KEY TAKEAWAYS
While quality, price, and advertising contribute to products and ideas being successful, word of
mouth drives 20 to 50 percent of all purchasing decisions. Word of mouth is more effective than
traditional advertising for two reasons:
It’s more persuasive. Word of mouth recommendations are more objective and
candid, so we are more likely to trust and listen to them.
It’s more targeted. We share information and stories with people who will find our
information relevant and interesting.
Contagious explains what makes products, ideas, stories, and news likely to spread from person to
person via word of mouth and social influence. There are 6 principles:
Principle Why it Works
Social How does it make people look to talk about a product or idea? Most people would
Currency rather look smart than dumb, rich than poor, and cool than geeky.
Triggers How do we remind people to talk about our products and ideas? Triggers are stimuli
that prompt people to think about related things.
Emotion When we care, we share. So how can we craft messages and ideas that make people
feel something?
Public Can people see when others are using our product or engaging in our desired
behavior? Making things more observable makes them easier to imitate, which makes
them more likely to become popular.
Practical How can we craft content that seems useful? People like to help others, so if we can
Value show them how our products or ideas will save time, improve health, or save money,
they’ll spread the word.
Stories What broader narrative can we wrap our idea in? People don’t just share information,
they tell stories.
Fleur Vanparijs Januari - CMM
, CONTAGIOUS
PRINCIPLE 1: SOCIAL CURRENCY
“WE SHARE THINGS THAT MAKE US LOOK GOOD”:
Social currency helps people look good to others. Most people would rather look clever rather than
dumb, hip rather than dull, and cool rather than geeky. There are three ways to generate social
currency:
1: FIND INNER REMARKABILITY
Remarkable things are unusual, extraordinary, or worthy of notice or attention. Something can be
remarkable because it is novel, surprising, extreme, or just plain interesting.
You can make your product remarkable by breaking a pattern that people have come to expect. For
example, it’s remarkable that the Blendtec blender can destroy an iPhone, and that a ball of glass will
bounce higher than a ball of rubber. It’s also remarkable that a low-cost airline like Jetblue provides
first-class amenities to all passengers.
2: LEVERAGE GAME MECHANICS
Game mechanics include rules and feedback loops that make things fun.
Building game mechanisms into your product (e.g., Airline frequent flier programs) lead people to
engage in certain behaviors (e.g., flying one airline even when it’s not convenient) and to talk about
their achievements (e.g., achieving Diamond status with an airline). Along the way, they spread the
word about brands.
3: MAKE PEOPLE FEEL LIKE INSIDERS
People enjoy feeling like insiders. There two mechanisms that make people feel like insiders:
carcity: how much of something is offered. Scarce things are less available, due to high
demand, limited production, or restrictions on a time/place to buy. For example,
Please Don’t Tell (NYC Speakeasy), only has 45 seats available.
Exclusivity: the availability of something based on particular criteria. For example, for
an invite-only website, you need to know an existing site member to get access.
By making people feel like insiders, scarcity and exclusivity boost word of mouth.
CAVEAT FOR DRIVING REFERRALS
In some cases, people who refer others to your product or service for free will stop referring people
once you start paying them. This happens because you have taken away the person’s intrinsic
motivation to share something helpful with a friend with a financial incentive that may feel “dirty.”
HOW TO EVALUATE SOCIAL CURRENCY
Does talking about your product or idea make people look good?
Can you find the inner remarkability?
Can you leverage game mechanics?
Can you make people feel like insiders?
Fleur Vanparijs Januari - CMM