Google+ was first announced nearly one month ago by the search giant as an invite-only service. However, Google+ has quickly become the fastest growing social network in history, reaching 10 million users in just over two weeks.
Paul Allen, co-founder of Ancestry.com, (not to be confused with Microsoft's co-founder who goes by the same name) has posted new data on his Google+ account, claiming that the social network may be hitting 18 million users in the coming hours, if it hasn't already. With that being said, Allen claims that Google+'s growth rate has dropped by 50% from its peak, which could mean two things: (1) people have given up on getting an invite, or (2) everyone who wants an account already has one.
Last week we saw two days where more than 2 million signed up in a single day. If that rate had continued, Google+ would have reached 20 million users by last Sunday night. But the last four days have averaged only 948,000 new users and yesterday the site added only 763,000. Yesterday's growth of 4.47% was the slowest viral growth since Google opened up invites back on July 6th.
In addition, Allen notes that the slow down in user growth may be due to the fact that Google hasn't been advertising its social network all that much, at least not yet.
The most followed person on Google+ is Facebook founder and CEO, Mark Zuckerberg (despite the fact that he doesn't have one thing posted on his profile). At time of writing, 272925 people have Zuckerberg in their Circles.