The web is undergoing a fundamental change. It is moving away from its current structure of documents and pages linked together, and towards a new structure that is built around people. This is a profound change that will affect how we create business strategy, design, marketing, and advertising. The reason for this shift is simple. For tens of thousands of years we've been social animals. The web, which is only 20 years old, is simply catching up with offline life.From travel to news to commerce, smart businesses are reorienting their efforts around people-around the social behavior of their customers and potential customers. In order to be successful, businesses will need to understand how people are connected, how their social network influences them, how the people closest to them influence them the most, and how it's more important for marketers to focus on small, connected groups of friends rather than looking for overly influential individuals.This book pulls together the latest research from leading universities and technology companies to describe how people are connected, and how ideas and brand messages spread through social networks. It shows readers how to rebuild their business around social behavior, and create products that people tell their friends about.