Overview
Wharton marketing professor Jonah Berger provides a six-principle framework (STEPPS) that explains the science behind word-of-mouth and social transmission.
Berger is a Wharton marketing professor who studied what makes things go viral — products, ideas, political messages. Contagious, published in 2013, introduces the STEPPS framework (social currency, triggers, emotion, public, practical value, stories) as the drivers of word-of-mouth. The book is part research, part case-study synthesis, aimed at marketers rather than the academic audience.
Key Ideas
Social Currency
People share things that make them look good.
Triggers Keep Ideas Top of Mind
Products linked to everyday cues get talked about more.
Stories are Trojan Horses
Embed your message within a compelling narrative.
Who should read this
Marketers, content creators, and product people trying to understand why some things spread. The chapters on triggers (environmental cues that remind people to talk about something) and on practical value (useful content people share to help others) are particularly actionable.
Who might skip it
Skip if you want meta-analyses or primary research — Berger popularises his and others' work, and specialists will find the treatment thin. Skip also if you dislike the STEPPS-acronym structure; the framework is the organising principle of the whole book.
The verdict
A well-made popular-research book. STEPPS is a serviceable checklist for evaluating content or product hooks before release, and I've used it in practice with reasonable results. The case studies are mostly 2000s-era American consumer examples and feel dated, but the framework still works.
"Word of mouth is the primary factor behind 20 to 50 percent of all purchasing decisions."
— Jonah Berger, Contagious
If you liked this
Made to Stick by the Heath brothers for the older related classic. Invisible Influence, Berger's follow-up, extends the social-proof material.