Sin conexión Google Mail. Plusone-button. Documentation You can add and customize the +1 button to meet the needs of your website, such as modifying the button size and load technique.
By adding the +1 button to your website, you allow your users to recommend your content to their circles and drive traffic to your site. The +1 button can also improve the time spent on your site by providing recommendations for further reading. Use of the +1 button is subject to the Google+ Platform Buttons policy.
Getting started. Herramientas para webmasters - Página principal.