According to an estimate by Paul Allen of Ancestory.com, Google+ has already crossed 10 million user mark — that makes it one of the fastest growing networks ever.
Allen has created an interesting formula to calculate number of Google+ members, according to which the 10 million number will be doubled by the end of this week. This is an impressive feat, as Google+ is still not open to public at large.
Allen tracked the growth and number of Google+ users by using names of existing members and compared them with the U.S. Census Bureau. According to ReadWriteWeb :
To determine these figures, Allen used surname-based analysis, a tactic he’s quite familiar with from the years he spent at Ancestry.com. His model uses U.S. Census Bureau data about surname popularity in the U.S. and compares it to the number of Google Plus users with each surname. He also split the U.S. users from the non-U.S. users in his analysis, since Google Plus is open in international markets, too.
Allen used a sample of 100 to 200 surnames to estimate the total percentage of the U.S. population who has signed up for Google Plus. He then used that number and a calculated ratio of U.S. to non-U.S. users (one U.S. user for every 2.12 non-U.S. users) to generate his worldwide estimates.
The results show Google Plus currently has approximately 9.5 million users worldwide, while around 2.2 million joined in the past 34 hours. These results can be trusted to some extent but not entirely — because the data comes from a third party and is not official.
With this growth rate, will it be enough to overtake Facebook which has more than 750 million users at this moment of time? Let us know in comments.