Google+ is Exploding. Millions Joining Daily. 30% Increase in Users in last 2 days.

Paul Allen posted this on his Google+ profile about 3 hours ago:

My team just completed a new round of counting Google+ users by surname. And I have updated my model. Our sampling of 400 uncommon surnames in the U.S. also reflects usage in many other countries, since the list of 400 includes names that are popular in India, Germany, Italy, France, Japan, and many other countries.

In the past couple of days, since Google opened its doors to the general public over age 18, the growth rate has skyrocketed to rates we only saw during the first week of its "field test" -- back when it had a small number of users to begin with, the growth rates were of course much higher.

But when I checked the data this morning, it is clear that Google+ is absolutely exploding -- 30% growth in just 2 days and with a base of nearly 30 million members already.

Here are my latest estimates:

On September 9, our model showed 28.7 million users
This morning, our model shows 37.8 million users, with most of the growth coming in the last 2 days
By adding a fudge factor (see below) to account for private user profiles and for non-Roman surnames (both of which are totally overlooked by our surname counting model), my current estimate is 43.4 million users

The timing on Google+ opening up to the public is interesting. Facebook has made a ton of UI changes this week and is holding it's F8 Developers Conference today - in fact it is just staring now. According to a survey this week by Mashable, 72.2% of Facebook users hate the recent UI changes, including the News Feed redesign. Twitter's stream was filled with complaints yesterday about Facebook under the hashtag #newfacebook.

Google is a company that has had the incredible discipline for more than a decade to use a very simple, minimalist design on its home page along with a long search box to encourage longer queries. Changes to home page links are very infrequent. The popularity of its home page never led Google to turn itself into a portal, with hundreds of links and a few lucrative ads. Given that discipline, I think the tens of millions of people who will be signing up for and using Google+ will find that changes here will be very well thought out, very iterative, very carefully tested, and won't be nearly as jarring as the changes that have been made at other social networks. Google is not in a rush to change the world. They are on a steady course to do so.

Notes about My "Fudge Factor":

My earlier model (see links below) which proved to be very accurate in the first 2-3 weeks, did not address either private profiles or non-Roman alphabet. According to FindPeopleOnPlus.com, there are substantial numbers of users from countries like Indonesia, China, Vietnam, Japan, Thailand, and many other countries, which my surname counting approach does not include. So I have decided to add a 5% privacy fudge factor and a 10% non-Roman alphabet fudge factor in my Google+ model. I'll need to develop a way to actually calculate those percentages somehow, rather than just guess on them.

For reference, here are my earlier posts on this subject:

*Google+ passes 10 million users on 7/12: http://bit.ly/pduDrG*

*4.5 million estimate on 7/9 (actually 12:15ish on 7/10): http://bit.ly/qUAxzt*

*1.7 million estimate on 7/4: http://bit.ly/pFm7oP*