This is a tag that is used to link the Google + profiles of users to their content. This helps increase the traffic within a webpage, and strengthens the branding and authority of a website.
Sean Si is a Filipino motivational speaker and a Leadership Speaker in the Philippines. He is the head honcho and editor-in-chief of SEO Hacker. He does SEO Services for companies in the Philippines and Abroad. Connect with him at Facebook, LinkedIn or Twitter. Check out his new project, Aquascape Philippines