Google+ (pronounced and sometimes written as Google Plus) is a social networking and identity service that is owned and operated by Google Inc. Google has described Google+ as a "social layer" that enhances many of its online properties, and that it is not simply a social networking website, but also an authorship tool that associates web-content directly with its owner/author. It is the second-largest social networking site in the world after Facebook. 540 million monthly active users are part of the Identity service site, by interacting socially with Google+'s enhanced properties, like Gmail, +1 button, and YouTube comments. In October 2013, Google counted 540 million active users who used at least one Google+ service, of which 300 million users are active in "the stream".
There are currently 540 million monthly active users across Google Properties and 300 Million active in the Google + Stream. Google+ user base is roughly 60% male and 25% female as of November 2013. The remainder are "Other" or unknown. Early adopters of Google+ in mid-2011 were mostly male (71.24%), and the dominant age bracket (35%) was between 25 and 34. An August 2011 survey estimated that 13% of U.S. adults have joined Google+; it was projected to have 22% of U.S. adults in a year.
On January 26, 2012, teenagers were finally able to create a Google+ account. The age limit had previously been 18, but in response to widespread and unprecedented demand on the part of American teenagers to be permitted to create a Google+ account, Google's Vice President for Product Management Bradley Horowitz eventually relented and announced on Google+ that users as young as 13 would be allowed to join the popular social networking medium.
According to Business Insider and TastyPlacement, having "Google+ followers boosts the [Google search] ranking the most, while a "+1" still does way more for your search ranking than Facebook or Twitter."
Source: Wikipedia
