Improve engagement through users' connections.
When users sign in with Google, they can now choose to bring their Google+ info with them (like their public profile, and the people in their circles). This lets your app welcome users by name, display their picture, connect them with friends, and lots more. A messaging app gets better with your best friends, just like a cooking app is more welcoming when it knows your name.
Create accurate profiles
Help users find other friends who use your service through their Circle connections on Google+. For instance, you can recommend people to follow in your app or help users recommend your app to their friends based on who they are connected to on Google+. By connecting friends and colleagues, you can build lasting relationships and grow user networks in your app.
Spark content discovery
Create dynamic marketing campaigns
Segment customers and identify influencers based on public information from your users’ profiles. This lets you tailor special offers and customize promotional content based on locale, age range, or size of their network. In addition, you can request users’ permission to communicate with them by email.