Contagious by Jonah Berger

A company publishes a beautifully produced video. Almost nobody shares it. A person posts a simple tip recorded on a phone. It travels everywhere. Quality matters, but quality alone does not explain transmission. Jonah Berger's Contagious looks at what happens in the moment between: "I saw this" and "Someone else needs to see this." He organizes the patterns into STEPPS.

Rather than treating them as a recipe for guaranteed virality, they are more useful as six different reasons a person might pass something along.

Social Currency: Sharing Can Say Something About the Sharer

You discover a restaurant nobody in your group knows. Telling them feels good. Partly because the restaurant is useful information. Partly because you become the person who knew about it. Sharing communicates identity. Funny. Informed. Helpful. Ahead of the trend. Generous. This changes a marketing question. Instead of only asking: "Will people like this?" ask: "What does sharing this allow someone to say about themselves?"

Triggers: Good Ideas Need a Way Back Into Memory

An idea can be excellent and still disappear after exposure. Triggers connect it to ordinary life. A day. A routine. A place. A repeated problem. When that situation appears again, the idea has another chance to return to mind. This is why some campaigns stay culturally present long after advertising stops. They have become attached to something people repeatedly encounter.

That relationship between triggers and repeated behavior also appears in Hooked, where Nir Eyal examines how cues can become connected to actions people begin repeating almost automatically.

Emotion: Indifference Rarely Travels Far

The content you immediately send to another person usually created some reaction. Surprise. Amusement. Anger. Awe. Excitement. Berger's point is not simply "make people emotional." That can produce manipulative nonsense very quickly. The stronger question is whether the idea gives people a reason to care enough to continue the conversation. If the emotional response is zero, sharing has little fuel.

Public: Visible Behavior Advertises Itself

People observe people. Which laptop appears in the cafe? What shoes are people wearing? What are coworkers using? What restaurant has a line? If product use is publicly visible, users themselves create exposure. That does not guarantee imitation. But invisible behavior cannot easily provide social evidence. Designing for observability can therefore influence how naturally a product travels.

Practical Value: Useful Information Makes the Sharer Useful

This is the least glamorous principle and possibly one of the most durable. A discount. A shortcut. A warning. A tool. A clear explanation. People share things that can help someone they know. Useful content gives the sharer a small gift to pass along. For creators, this matters because practical value does not require spectacle. A piece can spread because it solved a problem well.

Stories: The Message Needs a Vehicle

Facts are portable. Stories are often more portable. They contain people, tension, sequence, and an ending. But Berger adds an important warning. The product needs to remain connected to the story. A hilarious advertisement that everybody remembers while nobody remembers the brand created entertainment, not necessarily effective word-of-mouth. The strongest story cannot be retold properly without carrying the idea with it.

That focus on making the message survive inside the story also connects with Building a StoryBrand, where Donald Miller emphasizes organizing a message around a clear problem, guide, action, and outcome rather than overwhelming people with information.

STEPPS Is Not a Viral Button

Human behavior is too unpredictable for that. You can use all six principles and still produce something nobody shares. You can accidentally create something highly shareable without consciously using any of them. The framework is better used diagnostically. Before publishing: Does this help the audience express something? What will remind them of it later? Is there an emotional reason to care? Can people observe the behavior? Is it genuinely useful? Is there a story worth retelling?

Not every piece needs six yeses. The exercise simply forces the creator to think beyond "Is this good?" The more demanding question is: Why would one person actively give this to another? Virality cannot be ordered. A reason to share can be designed.