According to analysts if the Google+ invites keep flowing at the current pace, the search giant's social-networking site could count up to 20 million users by the end of the weekend.
In an attempt to arrive at a ball park estimate of Google+ users, Ancestry.com founder Paul Allen (not Microsoft co-founder) compared US Census Data with last names of certain Google+ members.
Early estimates released over the weekend put Google+ at about 4.5 million users, a figure that has since exploded according to Allen.
"My surname-based analysis shows that the number of Google+ users worldwide reached 7.3 million yesterday (July 10)-up from 1.7 million users on July 4th," Allen wrote in a Google+ post.
"That is a 350-per cent increase in six days. The user base is growing so quickly that it is challenging for me to keep up, since the number of users of any given surname (even the rare ones I am tracking) seems to be climbing every day."
What was more impressive he said was that it appeared that approximately 2.2 million people had joined Google+ in the last 32 to 34 hours, leading to a total of about 9.5 million people on Monday.