Introduction
Have you ever wondered why some products become wildly popular overnight while others fade into obscurity? In "Contagious: Why Things Catch On," marketing professor Jonah Berger reveals that virality isn't random luck or big advertising budgets—it follows specific, replicable patterns. The book provides a powerful viral content formula that businesses can apply to make their products and ideas spread naturally through word-of-mouth marketing. As traditional advertising loses effectiveness, understanding the science behind shareable content has become essential for marketers and businesses alike.
Purpose & Scope
Berger's central thesis is straightforward yet profound: Word-of-mouth transmission follows consistent, identifiable patterns that can be engineered into any product or idea. The book introduces the STEPPS framework—a systematic approach to product virality that organizations can implement regardless of budget or industry. By mastering these organic growth hacks, businesses can design offerings that naturally encourage people to share, discuss, and promote them to others.
Core Concepts & Themes
1. Social Currency: Making People Look Good
People share things that make them appear knowledgeable, cool, or in-the-know. Social currency functions as a psychological reward system—we gain status when we share valuable or impressive information. This principle explains why exclusive experiences, surprising facts, and insider knowledge spread rapidly.
Example: When Blendtec created their "Will It Blend?" YouTube series showing their blenders pulverizing everything from iPhones to golf balls, they transformed a mundane kitchen appliance into something remarkable. Sharing these videos made people seem entertaining and in-the-know. The company's sales increased by 700% after the campaign launched.
Strategies for Building Social Currency:
A. Inner Remarkability When products or ideas contain naturally surprising or extraordinary elements, they become conversation-worthy. Snapple capitalized on this by printing unusual "Real Facts" under their bottle caps, giving customers interesting tidbits to share with friends.
B. Game Mechanics People love achievements, status levels, and competition. Foursquare's early success came from awarding "mayorships" and badges that users proudly displayed, driving further engagement as people competed for status.
C. Exclusivity Things that are hard to get or known only to insiders naturally become valuable social currency. The NYC speakeasy "Please Don't Tell," accessible only through a secret phone booth entrance, thrived on exclusivity despite minimal advertising.
2. Triggers: Environmental Cues That Prompt Conversation
People talk about what's top of mind, and environmental cues—triggers—determine what we think about. Unlike one-time viral sensations, products associated with frequent triggers maintain steady word-of-mouth over time.
Example: Hershey's brilliant "Kit Kat and coffee" campaign associated the candy bar with a daily habit. By positioning Kit Kat as the perfect coffee companion, they ensured their product would come to mind whenever someone had a coffee break—which for many people happens multiple times daily.
Strategies for Effective Triggers:
A. Link to Frequent Stimuli The most effective triggers occur regularly in daily life. Rebecca Black's song "Friday" resurged in popularity every Friday because the day itself became a weekly trigger.
B. Grow the Habitat Boston Market increased word-of-mouth by 20% simply by associating their brand with dinner (a frequent occurrence) rather than just lunch.
C. Choose Strong, Unique Associations The best triggers have a single, powerful association. "Peanut butter" strongly triggers "jelly," while "red" has too many associations (Coca-Cola, Target, Valentine's Day) to be an effective trigger for any single brand.
3. Emotion: Feelings That Drive Sharing
Content that evokes strong emotions—particularly high-arousal emotions like awe, excitement, or anger—spreads faster than content that evokes low-arousal emotions like sadness or contentment. The physiological activation that accompanies these emotions drives people to share.
Example: Susan Boyle's Britain's Got Talent audition became one of the most viral videos ever because it evoked intense awe and amazement. The emotional roller coaster of seeing an unassuming woman deliver an extraordinary performance created a high-arousal emotional state that prompted millions to share the video.
Key Emotional Drivers:
A. High-Arousal Emotions (More Sharing)
- Awe: Scientific breakthroughs, incredible talents, or breathtaking natural phenomena
- Excitement: Product launches, unexpected successes, thrilling stories
- Anger: Outrageous behavior, injustice, provocative statements
B. Low-Arousal Emotions (Less Sharing)
- Sadness: Heartwarming but depressing content rarely spreads widely
- Contentment: Relaxing or satisfying content doesn't create urgency to share
The intensity of emotion matters more than whether it's positive or negative. Negative content can go viral if it evokes high-arousal emotions, like the famous "United Breaks Guitars" video that sparked outrage.
4. Public: Making Products and Behaviors Observable
People imitate what they see others doing. When behaviors or product usage are publicly visible, they spread more rapidly through social proof. Designing for observability—making private behaviors public—is a powerful strategy for increasing adoption.
Example: Apple's decision to flip their laptop logo was a masterstroke of observability. Previously, the logo appeared right-side up to the user but upside-down to everyone else. By reversing it, Apple ensured that every open MacBook became a walking billboard visible to others.
Strategies for Public Visibility:
A. Design for Observability Products that naturally display usage (like distinctive white Apple earbuds) spread faster than invisible ones (like brands of toothpaste).
B. Create Behavioral Residue Physical traces of behavior extend visibility beyond the moment of use. "I Voted" stickers not only signal civic participation but remind others to vote.
C. Leverage Public Behaviors The Movember Foundation transformed private support for men's health into a public behavior (growing mustaches), creating visible conversation starters.
5. Practical Value: Sharing Useful Information
People share useful information to help others. When content provides clear value—whether it's money-saving tips, time-saving hacks, or solutions to common problems—people share it out of genuine desire to assist friends and colleagues.
Example: Ken Craig, an elderly man who shared a simple corn-husking technique on YouTube, garnered millions of views because his method solved a common kitchen frustration. His video spread rapidly because viewers recognized its practical value and wanted to help others.
Strategies for Enhancing Practical Value:
A. Frame Deals Effectively How you present savings impacts shareability. For items under $100, percentage discounts seem larger (20% off $25); for items over $100, absolute discounts seem larger ($200 off $1,000).
B. Package Information Accessibly Vanguard's financial newsletters succeeded because they distilled complex financial advice into simple, actionable steps.
C. Provide Immediate Utility Content that solves immediate problems (like the 2-minute mug cake recipe) spreads faster than abstract advice.
6. Stories: Embedding Messages in Narratives
People think, remember, and share in narratives. Stories serve as "Trojan Horses" that carry embedded information and brand messages in a naturally engaging format. The key is ensuring your message is an integral part of the story, not just an add-on.
Example: Dove's "Evolution" video told a compelling story about unrealistic beauty standards by showing how photo editing transforms an average woman into a "perfect" billboard model. The narrative was so engaging that people shared it widely, carrying Dove's message about real beauty along with it.
Strategies for Effective Story Marketing:
A. Ensure Narratives Are "Valuable Virality" Stories must actually promote your product or idea. GoldenPalace.com's streaker stunt went viral, but because the casino's name wasn't integrated into the story, it generated buzz without business results.
B. Create Story-Worthy Experiences Extraordinary customer service (like Lands' End's legendary guarantees) generates stories that customers naturally share.
C. Make Your Brand Critical to the Narrative In Blendtec's "Will It Blend?" videos, the product's extraordinary power is central to the story—you can't retell the story without mentioning the blender.
Actionable Key Takeaways & Insights
1. Engineer Social Currency Into Your Product or Service
Actionable Steps:
- Identify what makes your offering genuinely remarkable or surprising
- Create a "secret menu" item or exclusive experience for customers
- Implement a visible achievement system (badges, tiers, recognition)
Example: Spotify's year-end "Wrapped" feature shows users their personal listening stats in shareable formats. People eagerly post their music tastes because it expresses their identity (social currency) and comes in easily shareable graphics (public).
2. Map Your Brand to Frequent, Strong Triggers
Actionable Steps:
- List daily routines or regular activities your target audience engages in
- Identify which routines naturally connect to your product's benefits
- Create marketing that explicitly links your brand to these triggers
Example: A breakfast cereal company could run a campaign connecting their product to morning workouts: "Fuel your morning run with [Brand]." This creates a trigger (morning exercise) that occurs daily for many people.
3. Evoke High-Arousal Emotions
Actionable Steps:
- Identify which high-arousal emotions align with your brand values
- Create content that builds emotional tension before release
- Test content for emotional impact before widespread release
Example: An environmental organization could create a video showing the transformation of a polluted beach into a pristine shoreline. This evokes both the anger of seeing pollution and the awe of witnessing restoration—both high-arousal emotions that drive sharing.
4. Make Private Behaviors Public
Actionable Steps:
- Add visible signals that identify users of your product
- Create shareable achievements users can display
- Design for "behavioral residue"—physical evidence that remains after usage
Example: Fitness apps that automatically post workout achievements to social media make exercise (typically private) into a public behavior, increasing both visibility and accountability.
5. Package Information for Maximum Utility
Actionable Steps:
- Distill complex information into clear, actionable steps
- Use the "Rule of 100" for framing discounts (percentages for under $100, absolute values for over $100)
- Optimize content for immediate application
Example: A cooking utensil company could create "5-Minute Dinner Hacks for Busy Parents" videos demonstrating quick meals using their products—practical value that serves an immediate need.
6. Develop Story-Worthy Experiences
Actionable Steps:
- Identify narrative-worthy elements in your customer experience
- Create remarkable service moments that customers will want to share
- Ensure your brand or message is essential to the story, not incidental
Example: Zappos' legendary customer service—like sending flowers to a customer who ordered shoes for her mother's funeral—creates stories that customers naturally share, with the brand message (extraordinary service) embedded in the narrative.
Notable Quotes
"People don't think in terms of information. They think in terms of narratives. But while people focus on the story itself, information comes along for the ride."
This quote highlights how narratives serve as vehicles for messages—when crafting content, focus on creating compelling stories rather than just conveying information. The most effective marketing doesn't feel like marketing at all.
"Contagious content typically contains some combination of Social Currency, Triggers, Emotion, Public, Practical Value, and Stories."
Here Berger summarizes his STEPPS framework, emphasizing that the most viral content often incorporates multiple principles simultaneously, creating a multiplicative effect.
"Just as people use money to buy products or services, they use social currency to achieve desired positive impressions among their friends and acquaintances."
This insight reframes how we think about sharing behavior—people aren't just altruistically sharing information; they're making calculated "investments" in their social image. Smart marketers create content that enhances this social ROI.
"If something is built to show, it's built to grow."
This elegant phrase captures the essence of the Public principle—visibility drives adoption through social proof. Products designed with public visibility in mind have a built-in advantage for spreading.
"Word of mouth is the primary factor behind 20 percent to 50 percent of all purchasing decisions."
This statistic underscores why understanding contagiousness matters so much—word of mouth influences purchasing decisions more than any other factor, especially for first-time purchases and experiential products.
Further Reading & Resources
"Made to Stick" by Chip & Dan Heath - Explores what makes ideas memorable using the SUCCESs framework.
"Influence: The Psychology of Persuasion" by Robert Cialdini - Examines the psychology behind persuasion and compliance.
"Hooked: How to Build Habit-Forming Products" by Nir Eyal - Details how to create products that form strong user habits.
"Positioning: The Battle for Your Mind" by Al Ries and Jack Trout - Discusses how to position products in consumers' minds.
"The Tipping Point" by Malcolm Gladwell - Analyzes how ideas and trends reach critical mass and spread rapidly.
Conclusion
"Contagious" transforms our understanding of virality from a mysterious phenomenon to a science with clear principles. The STEPPS framework provides a systematic approach to product virality that any organization can implement. By crafting shareable content that contains social currency, links to effective triggers, evokes emotion, remains publicly visible, provides practical value, and tells compelling stories, businesses can implement these organic growth hacks to achieve remarkable results. The book ultimately demonstrates that with the right word-of-mouth marketing strategy, even ordinary products can become extraordinarily contagious.