Dr. Berger is a marketing professor at the University of Pennsylvania, and author of the bestselling book, Contagious: Why Things Catch On. Berger has spent over 15 years studying how social influence works, and how it drives products and ideas. In addition to writing his book, he has published dozens of articles in top-tier academic journals and has consulted a variety of Fortune 500 companies. He has also been published in popular outlets like the New York Times and Harvard Business Review.

We've all seen products and ideas catch on, services and the like, whether it's a product in the grocery store (Greek yogurt became popular a few years ago), whether it's an app like Uber or Snapchat, or whether it is a service, like B2B marketing, for example. We've all seen examples of things which came out of nowhere and became extremely popular, and the question is "Why?" What was it about these things that made them popular?

It turns out that it's not just about advertising or having a big advertising budget, or even, necessarily, having the best product or service out there. It's really about the power of word-of-mouth. It turns out that word-of-mouth is ten times as effective as traditional advertising. If we can understand how to get that word-of-mouth, we can help our products and our services become more successful.