Contagious: Why Things Catch On

by Jonah Berger

Word of mouth is the primary factor behind 20 percent to 50 percent of all purchasing decisions.

traditional advertising is still useful, word of mouth from everyday Joes and Janes is at least ten times more effective.

Word of mouth is more effective than traditional advertising for two key reasons. First, it’s more persuasive.

Second, word of mouth is more targeted.

Word of mouth, on the other hand, is naturally directed toward an interested audience.

We don’t share a news story or recommendation with everyone we know. Rather, we tend to select particular people who we think would find that given piece of information most relevant.

Research by the Keller Fay Group finds that only 7 percent of word of mouth happens online.

Contagious content is like that—so inherently viral that it spreads regardless of who is doing the talking. Regardless of whether the messengers are really persuasive or not and regardless of whether they have ten friends or ten thousand.

Six key STEPPS, as I call them, that cause things to be talked about, shared, and imitated.

Principle 1: Social Currency How does it make people look to talk about a product or idea?

We need to find our inner remarkability and make people feel like insiders. We need to leverage game mechanics to give people ways to achieve and provide visible symbols of status that they can show to others.

Principle 2: Triggers

the more often people think about a product or idea, the more it will be talked about. We need to design products

and ideas that are frequently triggered by the environment and create new triggers by linking our products and ideas to prevalent cues in that environment. Top of mind leads to tip of tongue.

Principle 3: ...

So rather than harping on function, we need to focus on feelings. But as we’ll discuss, some emotions increase sharing, while others actually decrease it.

Principle 4: Public

Making things more observable makes them easier to imitate, which makes them more likely to become popular. So we need to make our products and ideas more public.

Principle 5: Practical Value

We need to understand what makes something seem like a particularly good deal. We need to highlight the incredible value of what we offer—monetarily and otherwise. And we need to package our knowledge and expertise so that people can easily pass it on.

Principle 6: Stories What

So we need to build our own Trojan horses, embedding our products and ideas in stories that people want to tell.

We need to make virality valuable. We need to make our message so integral to the narrative that people can’t tell the story without it.

contagious content often comes from applying principles that originally might have seemed unlikely. Heavy-duty blenders already have Practical Value, but Will It Blend? went viral because it found a way to give a blender Social Currency.

40 percent of what people talk about is their personal experiences or personal relationships.

neuroscientists Jason Mitchell and Diana Tamir found that disclosing information about the self is intrinsically rewarding.

Give people a way to make themselves look good while promoting their products and ideas along the way. There are three ways to do that: (1) find inner remarkability; (2) leverage game mechanics; and (3) make people feel like insiders.

But the most important aspect of remarkable things is that they are worthy of remark. Worthy of mention. Learning that a ball of glass will bounce higher than a ball of rubber is just so noteworthy that you have to mention it.

as many as 10 trillion frequent flier miles are sitting in accounts, unused.

Game mechanics are the elements of a game, application, or program—including rules and feedback loops—that make them fun and compelling.

Good game mechanics keep people engaged, motivated, and always wanting more.

People don’t just care about how they are doing, they care about their performance in relation to others.

Using scarcity and exclusivity early on and then relaxing the restrictions later is a particularly good way to build demand.

Every day, the average American engages in more than sixteen word-of-mouth episodes, separate conversations where they say something positive or negative about an organization, brand, product, or

Some word of mouth is immediate, while some is ongoing.

But what leads someone to talk about something soon after it occurs? And are these the same things that drive them to keep talking about it for weeks or months after?

As we suspected, interesting products received more immediate word of mouth than boring products. This reinforces what we talked about in the Social Currency chapter: interesting things are entertaining and reflect positively on the person talking about them.

Interesting products didn’t get any more ongoing word of mouth than boring ones.

But stimuli in the surrounding environment can also determine which thoughts and ideas are top of

accessible thoughts and ideas lead to action.

Market research often focuses on consumers’ immediate reaction to an advertising message or campaign. That might be valuable in situations where the consumer is immediately offered a chance to buy the product. But in most cases, people hear an ad one day and then go to the store days or weeks later. If they’re not triggered to think about it, how will they remember that ad when they’re at the store?

Triggers are the foundation of word of mouth and contagiousness. To use an analogy, think of most rock bands. Social Currency is the front man or woman. It’s exciting, fun, and gets lots of attention. Triggers could be the drummer or bassist. It’s not as sexy a concept as Social Currency, but it’s an important workhorse that gets the job done.

Triggers and cues lead people to talk, choose, and use. Social currency gets people talking, but Triggers keep them talking.

More interesting articles were 25 percent more likely to make the Most E-Mailed list. More useful articles were 30 percent more likely to make the list.

These results helped explain why health and education articles were highly shared. Articles about these topics are often quite useful. Advice on how to live longer and be happier. Tips for getting the best education for your kids.

Awe-inspiring articles were 30 percent more likely to make the Most E-Mailed list. Articles previously judged to have low Social Currency and Practical Value—Grady’s cough piece or an article suggesting that gorillas may, like humans, grieve when losing loved ones—nevertheless made the Most E-Mailed list because of the awe they inspired.

positive articles were more likely to be highly shared than negative ones.

Anger and anxiety lead people to share because, like awe, they are high-arousal emotions. They kindle the fire, activate people, and drive them to take action.

funny content is shared because amusement is a high-arousal

arousal emotion.