Contagious: Why Things Catch On Summary

“Contagious: Why Things Catch On” by Jonah Berger dives deep into the science of virality. It explains why certain products, ideas, and behaviors become wildly popular while others fail to gain traction. 

Berger outlines six key principles – social currency, triggers, emotion, public, practical value, and stories – that drive contagiousness. The book provides actionable strategies to make your messages and products more shareable, helping you create ideas that spread like wildfire.

Summary | The Six Key Principles

In the book, Berger challenges the conventional notion that viral success is about massive advertising campaigns or celebrity endorsements. Instead, he contends that the core driver behind things “catching on” is word-of-mouth.

To understand this phenomenon, Berger outlines six key principles that contribute to contagiousness:

1. Social Currency

• The Core Concept: People love to feel like insiders. If something makes them appear smart, savvy, in-the-know, or cool, they’re far more likely to share it. This desire for positive social image drives word-of-mouth. Imagine it like trading in reputational capital – what you say reflects on you.
• How to Apply It:
  • Remarkability: Find the naturally interesting or surprising angle of your product or idea. It needs to be noteworthy to break through the noise.
  • Game Mechanics: Introduce elements of competition, achievement, or exclusivity. Think about loyalty programs, tiered rewards for users, or limited-edition releases.
  • Make People Feel Like Insiders: Give early access, behind-the-scenes peeks, or access to knowledge not widely available. This fuels a sense of importance and fuels the desire to share.

2. Triggers

• The Core Concept: The environment constantly nudges our decisions and conversations. “Triggers” act as mental shortcuts connecting your idea or product with common cues so that it remains top-of-mind. Essentially, you want people to think of you whenever they encounter those triggers.
• How to Apply It:
  • Identify Common Triggers: What are frequent occurrences in your target audience’s life? Think days of the week (Taco Tuesdays), holidays, weather patterns, or even pop culture references.
  • Link Your Idea: Connect your product or idea to those triggers. This can be via slogans (“Got Milk?” linked to the moment when milk is consumed), associating your product with a particular time of day, or using seasonal cues.
  • Aim for Frequency: The more often the trigger occurs, the more frequently people will be reminded of your product or idea.

3. Emotion

• The Core Concept: When we care, we share. Content that evokes strong emotional responses in people, particularly high-arousal emotions, is far more likely to be passed on. This works because it physiologically excites a person, and in that excitement, they often seek social connection to share the experience.
• How to Apply It:
  • Focus on High-Arousal Emotions Awe, humor, excitement, even mild anxiety or anger, create an internal drive to share that surpasses content leaving someone neutral.
  • Don’t Neglect Positivity: While surprise and amusement are strong drivers, content that inspires feelings of contentment, wonder, or hope can also be highly contagious.
  • Kindness Counts: Things that make us feel good about ourselves or others make ideal sharing material. Tap into that desire to leave a positive mark on someone else’s day.

4. Public

• The Core Concept: We imitate what we see. This is known as social proof – if people observe others using a product, adopting an idea, or engaging in a certain behavior, they’re more likely to follow suit. It’s a shortcut for determining what’s “right” in a situation.
• How to Apply It:
  • Boost Visibility: Make your product or idea publically observable. This could be prominent logos, eye-catching product design, or causes signified by wearable symbols (think awareness ribbons).
  • Design for Social Sharing: Products with built-in shareability stand out. Consider something like Apple’s distinctive white earbuds, which became a subtle signifier of the product.
  • Leverage the “Apple Store Effect”: Crowds signal value. Even online, showcasing testimonials, user counts, or social media buzz creates the perception that many people are already on board.

5. Practical Value

• The Core Concept: People love helping others. Providing genuinely useful information, products that save time or money, or anything that improves someone’s life, fuels word-of-mouth. It’s a way to add value to our social interactions.
• How to Apply It:
  • Highlight Incredible Usefulness: Don’t just list features; demonstrate how your product or idea solves a problem in a remarkable way.
  • Emphasize Savings: Whether it’s money, time, or hassle, make it clear how people benefit directly.
  • Tap into Expertise: If you have knowledge in a field, sharing tips and tricks freely makes people want to pass on that value to others.

6. Stories

• The Core Concept: We are wired for narratives. Rather than simply spewing facts, products or ideas that are embedded within stories are more memorable and easier to share. Think of a story as a “Trojan Horse” – your message is the thing hidden inside the entertaining narrative.
• How to Apply It:
  • Don’t be Overtly Salesy: Focus on a story that naturally highlights the value of your product or idea, rather than a blatant advertisement.
  • Tap into Emotion: Good stories evoke feelings. Connect with your audience on an emotional level to make them invested.
  • Create a Shareable Structure: Is there a relatable character? A satisfying turning point? These elements make stories easier to retell.

Key Lessons

Small tweaks can lead to big differences

One of the core messages Jonah Berger emphasizes is that virality isn’t always about a massive overhaul. 

Often, subtle adjustments to the framing or presentation of an idea or product can make a tremendous difference in how readily it spreads. He cites examples like a hot dog vendor strategically placing a high-priced option on the menu, leading to a boost in sales overall, or how minor shifts in wording can significantly affect sign-ups for charitable causes. 

These examples showcase the importance of not overlooking seemingly minor details when trying to make something contagious.

Don’t focus exclusively on influencers

While endorsements from celebrities or influential people can be a boost, Berger stresses that lasting impact relies heavily on everyday word-of-mouth. 

Think of it as a ripple effect – a positive experience or a cool discovery shared with friends, who then share it with their friends, and so on. This grassroots spreading might be less flashy, but it’s incredibly potent for building lasting traction. 

It reinforces the idea that anyone can be a catalyst for making something go viral if the product or idea genuinely resonates with them.

Virality isn’t about making something simply amazing

Berger warns that a truly exceptional product or incredibly moving idea isn’t a guarantee of widespread success. 

If these amazing things don’t also align with the principles of contagiousness, they risk languishing in obscurity. A product needs to be talked about, it needs to have an element that sticks in the mind, and it needs to be easily observable by others to get the social transmission ball rolling. 

This highlights the need for a strategic approach, even if the core “thing” itself is already strong.

Final Thoughts

“Contagious” provides a compelling framework for marketers, innovators, and anyone who desires their ideas and products to gain traction. 

It demonstrates how understanding the hidden mechanisms of social transmission can be harnessed to turn the tide for successful launches, the widespread adoption of causes, or simply making your next dinner party the talk of the town.