Our barista, our mechanic, our coworker—they populate our days, but we often take them for granted. Yet these are the people who bring novelty and information into our lives, allow us to exercise different parts of ourselves, and open us up to new opportunities. In their unprecedented examination of people on the periphery, psychologist Karen Fingerman, who coined the term “consequential strangers,” collaborates with journalist Melinda Blau to expand on and make her own groundbreaking research come alive. Drawing as well from Blau’s more than two hundred interviews with specialists in psychology, sociology, marketing, and communication, the book presents compelling stories of individuals and institutions, past and present. A rich portrait of our social landscape—on and off the Internet—it presents the science of casual connection and chronicles the surprising impact that consequential strangers have on business, creativity, the work environment, our physical and mental health, and the strength of our communities.