Google+ may have already crossed the 10 million user mark, says Paul Allen, founder of Ancestory.com which is the world's largest for-profit genealogy website.
More impressively, he believes that the social networking service has seen a 30% jump in growth and 2.2 million people could have joined in the last 35 hours alone. At this rate, he expects Google+ will achieve the 20 million user mark by the weekend.
In his Google+ post, Allen has explained how he arrived at these numbers.
He states "My model is simple. I start with US Census Bureau data about surname popularity in the U.S., and compare it to the number of Google+ users with each surname. I split the U.S. users from the non-U.S. users. By using a sample of 100-200 surnames, I am able to accurately estimate the total percentage of the U.S. population that has signed up for Google+. Then I use that number and a calculated ratio of U.S. to non-U.S. users to generate my worldwide estimates. My ratio is 1 US user for every 2.12 non-U.S. Users."
Ever since its launch, Google+ has stirred up the world of social networking, capturing public imagination by restricting invites, making the social network seem like an exclusive club that people want to get into.
In-spite of many poor previous attempts at social networking, Google seems to have finally come up with a worthy challenger to the might of Facebook which has been receiving critical acclaim for it's innovative privacy and video chat functionality
If the total user base of Google+ is anywhere near what Paul Allen believes, then Facebook will have an epic battle brewing in its backyard.