Google+, the search giant's second true attempt at a social network, has amassed more than 20 million users in roughly three weeks.
But Google+'s swift success somewhat mirrors the trajectory Google saw with the oft-maligned Google Buzz, which also came out of the gate hot and drew in millions of users in a short period of time.
According to statistics from ComScore, a Web traffic and analytics firm, more than 20 million unique people have visited Google+ since the launch of its field trial on June 28, and five million of those have been from the U.S., The Wall Street Journal reported.
Twenty million users in three weeks for an invite-only service is remarkable, and industry watchers expect an even bigger influx of users once Google+ hits general availability. Google has not yet said when Google+ will be open to all users, but earlier this week Google launched a Google+ app for the Apple iPhone.
"It is definitely the fastest ascent to 20 million visitors that I can think of," said Andrew Lipsman, ComScore's vice president of industry analysis told the Los Angeles Times.
Google created Google+ to do battle in the social networking and social media trenches against incumbents Facebook, which has an estimated 750 million users, and micro-blogging wunderkind Twitter with its 200 million registered users.
And Google last week said it is putting a great deal of weight behind its fledgling social network, which lets users lump friends, colleagues, acquaintances and others into "circles" based on relationships and share content, comments, photos and other information only with each circle or with all contacts.
Google+'s user numbers have doubled in just over a week. During Google's quarterly earnings call on July 14, CEO Larry Page said Google+ had just crested the 10 million user mark.
"So while we have a lot of work still to do, we are really excited about our progress with Google+," Page said, during the earnings call in which he said Google will re-focus on its core products and on new innovations. "Google+ is also a great example of another focus of mine -- beautiful products that are simple and intuitive to use and was actually was one of the first products to contain our new visual redesign."
But Google+ isn't Google's first foray into the world of social media and its celebration over 20 million Google+ users may be premature. Google launched its first social networking play Google Buzz in February 2010 and immediately saw user numbers swell, but Google Buzz was later panned.
"It's been just two days since we first launched Google Buzz. Since then, tens of millions of people have checked Buzz out, creating over 9 million posts and comments. Plus, we're seeing over 200 posts per minute from mobile phones around the world," Todd Jackson, Product Manager of Gmail and Google Buzz, wrote in a blog post about Google Buzz at the time.