Jonah Berger, Author, James G. Campbell Assistant Professor of Marketing at the Wharton School at the University of PennsylvaniaLast night, Jonah Berger, author of The New York Times bestseller “Contagious,” posed an interesting question to a packed room during an Authors@Wharton event.

Which product gets the most word of mouth buzz?

a) Walt Disney World
b) Honey Nut Cheerios
c) Scrubbing Bubbles

He took a poll by show of hands—and the audience didn’t exactly nail it.

“No one really seems sure about their choice, and it seems like we’re evenly split across all three of these options,” Berger told the crowd. “There’s your proof that if we had to guess, we’d likely get it wrong. But the answer is Honey Nut Cheerios.”

That quick poll proved a point. Word of mouth marketing isn’t easy to understand. And if we can’t understand word of mouth, generating word of mouth for products, services, and brands becomes incredibly difficult.

Still not sold on why that’s important? Berger pointed to McKinsey research that found “word of mouth generates more than twice the sales of paid advertising in categories as diverse as skincare and mobile.” In addition, referred customers have been found to have a 13% higher lifetime value, proving that word of mouth drives what you might call qualified leads.

And that’s where “Contagious” comes in. The book is an examination of why certain things go viral and generate that precious buzz, while other things don’t.

To get an answer to that question, Berger and his colleagues researched all of the articles in The New York Times for a six-month period to determine why certain content was shared more often and generated more buzz. And the research revealed that certain principles held true across the board for the most popular content.

“Word of mouth has a big causal impact on behavior,” Berger explained. “A big part of that is because it’s targeted. Nobody tells a friend who doesn’t have a baby about a new baby product. Instead, we talk about things we know will help each other.”

That finding leads into Berger’s research on word of mouth and virality. According to Berger, there are six principles that lead to something going viral:

– Social Currency
– Triggers
– Emotion
– Public
– Practical Value
– Stories

So let’s go back to Honey Nut Cheerios. Why do Honey Nut Cheerios generate more buzz than Walt Disney World?

ContagiousBecause Honey Nut Cheerios are tied to what Berger calls a trigger. People eat breakfast every morning, and that means that they’re more likely to talk about Honey Nut Cheerios on social networks and to their friends on a regular basis. As a result, Honey Nut Cheerios stays top of mind.

Meanwhile, someone who just went to Disney World might recommend the trip to their friends, but it’s not likely those friends will jump on a plane and fly to Florida the next day. The trigger is too infrequent.

Although this is just an example of one of Berger’s six principles, the rest of his research proves equally compelling. He discussed how we also make choices about what to discuss with friends in order to make ourselves look smart and “in the know,” which is why secret restaurants in New York City and “exclusive” emails from LinkedIn resonate and drive word of mouth.

“Contagious” is a thorough examination of what makes something go viral, and we’d call it a must-read for any online marketer looking for ways to create website content and experiences that drive conversions and word of mouth buzz.