Google+ the service was launched on June 28, 2011, in an invitation-only "field testing" phase. Early invites were soon suspended due to an "insane demand" for new accounts. On September 20, 2011, Google+ was opened to everyone 18 years of age or older without the need for an invitation. It was opened for a younger age group (13+ years old in US and most countries, 14+ in South Korea and Spain, 16+ in Netherlands) on January 26, 2012.
Google+ integrates social services such as Google Profiles and Google Buzz, and introduces new services identified as Circles, Hangouts and Sparks. Google+ is available as a website and on mobile devices. Sources such as The New York Times have declared it Google's biggest attempt to rival the social network Facebook, which has over 800 million users. Google+ is considered the company's fourth foray into social networking, following Google Buzz (launched 2010, retired in 2011), Google Friend Connect (launched 2008, to be retired by March 2012) and orkut (launched in 2004, now operated entirely by subsidiary Google Brazil).
On January 19, 2012, it was reported that Google+ had surpassed a user base of 90 million. According to independent analysis of its growth in December 2011, the site was adding an estimated number of 625,000 new users a day, which may total 400 million members by the end of 2012. The site's popularity accelerated in December 2011, with almost a quarter of its total user base joining in December alone, said Paul B. Allen, the founder of Ancestry.com, who tracks the numbers as the "unofficial statistician" for Google+. However, on February 28, 2012 Todd Wasserman from Mashable reported Google+ users are only spending 3.3 minutes monthly on Google+ which is a downward trend from 4.8 minutes in December and 5.1 minutes in November compared to Facebook users currently spending 7.5 hours using Facebook monthly.
Infographics by Chirsbrogan.com