Contagious
Word-of-mouth and virality using STEPPS
Engineer word-of-mouth and make your product go viral using Jonah Berger's STEPPS framework. This skill equips your AI agent with the science of why things catch on — from social currency to triggers to public visibility.
npx skills add wondelai/skills/contagious --global 
Contagious Jonah Berger View on Amazon
02 What it is
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.
03 Key concepts
Five principles your agent applies.
Drawn from Contagious — not advice it repeats back to you, but decisions it makes while it works.
04 Fit
When to use it, and
when not to.
four symptoms it fixes, and four it doesn't.
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.
05 Prompts
Say it like this.
Name the skill at the end of a prompt and the agent applies the framework rather than a vibe. Or say nothing — it loads on its own when a task matches.
Apply the STEPPS framework to my product launch plan using contagious skill
Create a referral campaign that leverages social currency using contagious skill
Find trigger opportunities for my productivity app using contagious skill
Make my feature announcement more shareable using contagious skill
06 About the author
07 Same stack
The stack it sits in.
Six Marketing & Messaging skills. Most people run two: this one, and whichever fits the next problem.
All Marketing & Messaging skills08 Questions
Before you install.
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.
09 Guides that use it
Put it to work.
Long-form playbooks where this skill does part of the job.
One skill, one command.
Install Contagious, or the whole stack.
npx skills add wondelai/skills/contagious --global MIT licensed · Claude, Claude Code, Codex, Cursor, OpenClaw, Hermes · No account