# Contagious

> Word-of-mouth and virality using STEPPS — an AI agent skill based on *Contagious* by Jonah Berger.

Published 2026-02-19 · Updated 2026-08-17 · Marketing & Messaging · Free and MIT-licensed
Canonical: https://skills.wondel.ai/skills/contagious/
Source: https://github.com/wondelai/skills/tree/main/contagious

**Install:** `npx skills add wondelai/skills/contagious --global`

## What is the Contagious skill?

Contagious packages Jonah Berger’s book on why things catch on into a free skill your AI agent loads when something has to spread. It audits a feature, campaign or piece of content against STEPPS — Social Currency, Triggers, Emotion, Public, Practical Value, Stories — scores each driver, and redesigns the weakest into something people have a reason to repeat.

## Key concepts from Contagious your agent applies

- **Social Currency** — People share things that make them look good — give them remarkable content worth talking about.
- **Triggers** — Link your product to everyday cues so people think about it frequently and share it naturally.
- **Emotion** — Content that evokes high-arousal emotions (awe, excitement, anger) gets shared more than low-arousal content.
- **Public Visibility** — Make usage visible — when people can see others using your product, they're more likely to adopt it.
- **Practical Value** — People share useful information. Package your content as advice, tips, or money-saving insights.

## When to use Contagious — and when not to

Reach for it when:

- Your launch got polite applause, a few likes, and precisely zero conversations you did not start yourself.
- Referrals only happen when you ask, because nothing in the product prompts a customer to mention it.
- You publish genuinely useful content that nobody forwards, cites in a meeting, or screenshots into a group chat.
- Nothing in a customer’s normal week reminds them you exist between the moments they actively need you.

Reach for something else when:

- The idea is forgettable before anyone considers sharing it — fix recall first with Made to Stick.
- You need formal invite mechanics, incentives and density metrics — that is Cold Start Problem territory.
- The goal is getting one visitor to act now, not to tell someone — Influence Psychology works that moment.
- You are optimising a conversion step you can already measure — CRO Methodology tests, this one designs.

## About Jonah Berger

Wharton marketing professor and viral behavior researcher. Jonah Berger is a Wharton professor who has spent over 15 years studying why products, ideas, and behaviors catch on. His research on social influence and virality has been published in top academic journals.

More: https://en.wikipedia.org/wiki/Jonah_Berger · https://www.wikidata.org/wiki/Q16246932
The book: https://openlibrary.org/books/OL26924173M/Contagious

## Example prompts

- Apply the STEPPS framework to my product launch plan using contagious skill _(Launch strategy)_
- Create a referral campaign that leverages social currency using contagious skill _(Growth marketing)_
- Find trigger opportunities for my productivity app using contagious skill _(Behavioral design)_
- Make my feature announcement more shareable using contagious skill _(Content marketing)_

## Frequently asked questions

### How do I install the Contagious skill?

Run `npx skills add wondelai/skills/contagious --global`. It takes about 30 seconds and needs no account. The Contagious skill then works in Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw and Hermes Agent — anything that reads the open agentskills.io format — and your agent loads it on its own when a task calls for it. It is free and MIT-licensed, and the source is at https://github.com/wondelai/skills.

### Which book is the Contagious skill based on?

It packages *Contagious* by Jonah Berger — wharton marketing professor and viral behavior researcher. The skill distils the book's method into instructions your agent follows while it works, covering social currency, triggers and emotion. It sits in the Marketing & Messaging part of the library.

### How is Contagious different from Made to Stick?

Made to Stick is about the receiver: will one person understand and remember this? Contagious is about the next hop: does that person gain anything — status, usefulness, a story worth telling — by passing it along? An idea can be perfectly memorable and completely unshareable. They compose well, and the STEPPS audit will often send you back to make a message concrete enough to survive being retold by someone who was not paying full attention.

### What does STEPPS stand for, and do I need all six drivers?

Social Currency, Triggers, Emotion, Public, Practical Value, Stories. Berger treats them as multipliers rather than a checklist — two done deliberately beat six done weakly. The skill scores each driver zero, one or two, maps the raw total onto a ten-point score, and names the single driver to raise next. It also runs the Trojan Horse test: if the story still works with your brand removed, the story has failed.

### Can this actually make something go viral?

No, and viral is the wrong target. Berger’s research puts roughly 93% of word-of-mouth in offline conversation, so the goal is not a spike on social but more people mentioning you more often. What the skill reliably does is remove the reasons nobody shares — no status payoff, no environmental trigger, no visible usage, no retellable story. Whether the market finds it worth talking about remains the market’s decision, not the framework’s.

### Does this only apply to consumer products and social content?

No. B2B is where Triggers and Practical Value pay best: a benchmark report people cite in meetings, a metric your product owns that becomes the phrase a team uses daily, an annual summary a manager forwards to a peer. The skill will run STEPPS over a pricing page, an onboarding email or a changelog as readily as over a campaign. The psychology of sharing does not change with the audience’s job title.

## Related

- All Marketing & Messaging skills: https://skills.wondel.ai/skills/marketing/
- StoryBrand Messaging: https://skills.wondel.ai/skills/storybrand-messaging/
- Made to Stick: https://skills.wondel.ai/skills/made-to-stick/
- 1-Page Marketing Plan: https://skills.wondel.ai/skills/one-page-marketing/
- Scorecard Marketing: https://skills.wondel.ai/skills/scorecard-marketing/
- Obviously Awesome: https://skills.wondel.ai/skills/obviously-awesome/