Although there is already buzz about how long it will take Google+ to achieve 100 million users, tech insiders are expecting to surpass the 10 million-mark by the end of today.
Ancestry.com founder and self-described "serial entrepreneur" Paul Allen is predicting on his Google+ page (of course) that the Goog's entry into the social networking world will have 10,000,000 active members by the end of Tuesday, July 12 based on the following calculations:
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. That is a 350% increase in six days. The userbase [sic] 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.
More impressive than last week's growth is the astonishing growth in users from yesterday at mid-day to tonight -- a 30% jump. My latest estimate tonight shows approximately 9.5 million users. This suggests that 2.2 million people have joined Google+ in the past 32-34 hours.
Allen adds that the figure could double by the end of this weekend. Paraphrasing Facebook CEO Mark Zuckerberg, Allen reminds us that "it is easy to underestimate the power of exponential growth."
Remember that joining Google+ is still on an invite-only basis, which makes this a fairly impressive feat. It would be unwise to compare how long it took Facebook to reach this point as social media in the mid-2000s just wasn't what it is now. Additionally, Google already has a built-in base of Gmail and other Apps users, so that only filters into this building base of subscribers more easily.
Additionally, it should be noted that this is just one person's hypothesis loosely based on mathematical formulas used for the United States Census. Google itself has not released any official numbers updating us on how many Google+ members there are yet, so this is definitely not 100 percent accurate. However, if these numbers are accurate, it would hardly surprise anyone at this point.