On Saturday Allen announced via Google+ that he is investigating how many users the new service has using a model Census data on how many people live in the U.S. with each surname. He estimates there are around 4.7 million Google+ users in the U.S. He said that number is up from 1.7 million he calculated earlier in the week.
He admits there are some shortfalls to his method when trying to calculate non-U.S. users, but he stands behind his work.
“… I haven’t seen a better methodology from anyone else yet about estimating Google+ growth, so I’ll continue to work on this one,” Allen says. He expects to have a more accurate estimate on Monday.
Another Google+ user, Atul Arora, says in Allen’s thread that you can gauge the number of Google+ users by running a Google Search for “inurl:plus.google.com/*about site:plus.google.com”.
At the time of posting I got about 6,430,000 results from running the search.
Sure, you should take these numbers with a grain of salt, but we do know that Google’s Executive Chariman Eric Schmidt told TechCrunch‘s Alexia Tsotsis on Thursday that there are millions of people in the beta. At least both these methods end up somewhere in that range.