Plus the Google button is very easy to integrate into your website. Also it will help to do seo of a website.
The functions of the buttons are similar to the Facebook -like button.
The message is divided in the profile of the user who is making the plus button.
Before the parts he can decide which groups the message is published.
The big difference between Google and Facebook plus that you can organize his contacts directly into different groups and the messages you want to read every day from each group (circles) is also can hide if you want to read only messages of certain groups. Most likely, the clicks appear on the Plus button on the placement of a website in Google ranking.
Because of Webmaster tools from Google appear to statistics about the clicks from Google plus.
This shows in detail how many users have visited the site on Google plus.