With the emergence of online social network sites and web 2.0 applications, social interactions, online collaboration, citizen journalism, information sharing, and e-commerce have become easier than ever. Human-generated data has become available on social media at an unprecedented scale, providing numerous opportunities for analyzing human behavior, mining human behavior, and investigating means to steer human behavior at scale. Finding digital traces of human behavior hidden among millions of social interactions, textual and multimedia content enables conducting research in social sciences, anthropology, psychology, and economics at scale. For industrial applications, these patterns help understand the social media ecosystem better, in turn unleashing full potential to market billions of users.