10Oct2025
Why do some products, ideas, and movements catch on while others fade away? During his Nordic Business Forum 2025 VIP session, Jonah Berger, Marketing Professor at the Wharton School, showed that it’s not about luck. It’s about science.
Jonah has spent over a decade researching word of mouth and social influence. His bestselling book Contagious: Why Things Catch On revealed why certain ideas spread and how leaders can use those insights to drive growth. On stage in Helsinki, he reminded us of a simple truth: it’s not enough for something to be good; it has to be shared.
Word of Mouth Beats Advertising
Every leader wants their message to spread. But as Jonah explained, traditional advertising rarely gets the job done.
“Word of mouth generates more than twice the sales of traditional advertising.”
The reason is simple: trust and targeting. We trust friends and colleagues more than we trust ads. And when people share, they don’t just broadcast randomly. They pass ideas on to those most likely to care.
Jonah illustrated this with a story about publishers who sent him two copies of a book, one for him and one to share. He didn’t give the extra copy to a random person. He gave it to the colleague who would appreciate it most. That’s targeting in action.
And while many assume word of mouth is mostly online, Jonah revealed a surprise: only 20% of word of mouth happens on social media. The rest still takes place face-to-face: over breakfast, during meetings, or at the bar after work.
“It’s not about the technology. It’s about the psychology.”
The Six Drivers of Why Things Catch On
Jonah’s research identified six psychological factors that drive people to share. He organized them in a simple framework called STEPPS:
- Social Currency: We share things that make us look good.
- Triggers: We talk about what’s top of mind.
- Emotion: When we care, we share.
- Public: What’s easy to see is easy to imitate.
- Practical Value: Useful information gets passed along.
- Stories: Narratives act as Trojan horses for ideas.
Though he only had time to dive into a few, the lessons were clear: If you want people to talk about your ideas, you need to build them with these psychological levers in mind.
Make People Look Good: Social Currency
We don’t just share for the sake of it. We share to signal who we are. From posting vacation photos to bragging about airline loyalty programs, people talk about things that make them look smart or special.
“The best way to get people to talk about us is to make them look good.”
Jonah told the story of a hidden New York bar, “Please Don’t Tell,” that has no sign outside and is accessible only through a phone booth in a hot dog restaurant. Because it feels like a secret, it gives visitors insider status, and they can’t resist talking about it.
Even the most boring products can find their “inner remarkability.” Jonah shared how Blendtec created viral success by filming its CEO blending unusual objects like iPhones. A $50 marketing budget turned into 200 million views and a 700% sales increase. The lesson is that if a blender can be remarkable, anything can.
Stay Top of Mind: Triggers
We don’t talk about what we like most; we talk about what’s top of mind. That’s where triggers come in.
The classic example: peanut butter and jelly. Peanut butter doesn’t just remind you of itself. It automatically makes you think of jelly. Smart brands link themselves to frequent triggers.
Kit Kat did this by pairing itself with coffee. Every time people reached for a cup, they thought of the chocolate bar too.
“Top of mind means tip of tongue.”
In other words, leaders should ask themselves: What’s our peanut butter? What’s the everyday cue that will make people think of us even when we’re not there?
Trojan Horse Stories
Facts fade, but stories travel. The most effective ones are what Jonah calls Trojan horse stories: engaging tales that smuggle the brand or idea inside.
The Blendtec videos weren’t just entertaining. They left one lasting message: the blender is powerful. People shared the story, but the brand came along for the ride.
“Good stories aren’t just stories. They’re vessels that carry ideas along the way.”
For leaders, this means thinking less about pitching and more about storytelling. Because people don’t tell “bedtime facts”, they tell bedtime stories.
Bringing It All Together
Jonah closed with a reminder that virality isn’t magic; it’s a method.
“It’s not random, it’s not luck, it’s not chance. There’s a science behind why people talk and why they share.”
By focusing on the psychology of sharing, leaders can turn employees into advocates, customers into ambassadors, and ideas into movements.
Jonah Berger’s Keynote Visual Summary by Linda Saukko-Rauta
Key Points and Questions for Reflection
Key Points
- Word of mouth is more powerful than advertising, and is more trusted and targeted.
- Only 20% of word of mouth is online. Most happens face-to-face.
- Jonah’s STEPPS framework outlines six drivers of sharing: Social Currency, Triggers, Emotion, Public, Practical Value, and Stories.
- To spread ideas, make people look good, link yourself to frequent triggers, and build Trojan horse stories.
- Even “boring” products can spread if you find the inner remarkability.
Questions for Reflection
- What makes your product, idea, or message worth talking about?
- How can you help your audience look good by sharing your message?
- What’s your “peanut butter”, the everyday trigger that will remind people of you?
- Is there a story you could tell that carries your core message inside it?
- How could you turn your existing customers or colleagues into advocates?
