Google+ is a social network owned by Google that allows users to build profiles, share content, and connect with others. It has over 300 million users but many accounts are inactive. Google integrates Google+ into many of its products and services. The document discusses key features of Google+ including Hangouts, Communities, Offers, and analytics tools. It also provides case studies on how brands like Cadbury, ESPN, and The Oatmeal have successfully used Google+. The document aims to help other brands understand how to leverage Google+ effectively.