Josh Quittner of Time magazine analyzed Google's potential strategic goal of pushing iGoogle with the recent "artist themes" logo, concluding it's a move against Facebook... as OpenSocial is part of Google's widget approach. An interesting bit from the article: "iGoogle currently accounts for 20 percent of visits to Google's home page," according to a Google. (Not sure if that's just measuring the US homepage, though – there's much too little background given on this number.)

http://www.time.com/time/business/article/0,8599,1736489,00.html

This would surprise me. Most of the people I know (outside of tech circles) haven't even heard of iGoogle.

" * There are tens of millions of active users on iGoogle worldwide
   * iGoogle was one of the fastest growing Google products in 2006 and 2007, and continues to grow
   * Approximately 50% of iGoogle users are in the U.S., with large user bases in the U.K., France, Japan, Germany, Canada, Spain, Italy, and the Netherlands as well
   * iGoogle is available in 42 languages and 73 domains"
http://code.google.com/apis/igoogle/docs/users.html

You could also find the no. of users by adding the numbers listed for each iGoogle theme: http://www.google.com/ig/directory?type=themes&sort=users (even though some users might use more than one theme)

Classic – 16,431,398
Beach – 1,121,943
Sweet Dreams – 607,683
Solar System – 482,588
Live Planet – 468,873
Spring Scape – 458,442
etc.

Probably the number is around 30 million users.

Here's a chart from comScore for Nov. 2007:

http://www.techcrunch.com/wp-content/goognumbers.jpg
(http://www.techcrunch.com/2007/12/22/2007-in-numbers-igoogle-googles-homegrown-star-performer-this-year/)

Google Search: >500 mil. vs iGoogle: 22.5 mil. (unique visitors)

for some location, if you go on google.com without ever been logged in to a Google Account, the first page you will see is iGoogle, saying "Welcome to iGoogle, your home on the web".
It's a kind of auto-hijacking...

That's because you've previously clicked on iGoogle and set a preference in the cookie.

Clicking on iGoogle's link has two effects:
- set a preference that all visits to google.com will be redirected to iGoogle
- go to google.com/ig

When I want to go to iGoogle, I type igoogle.com in the address bar.

Oh, I didn't notice the obvious: the number of iGoogle's unique visitors may be 5% from Google's visitors, but those people visit iGoogle more often to check their news, agenda etc. So 5% of Google's visitors could account for 20% of all visits.

Might also be that among iGoogle users, significantly more (or less) use Google as their browser homepage (loading it up whenever the browser starts). A number that would be interesting to know is how many users who are logged in currently switched to iGoogle.

"That's because you've previously clicked on iGoogle and set a preference in the cookie."
I installed Ubuntu on a friend's laptop, the default page was google.fr/firefox. So I changed it to google.fr. It redirected automatically to iGoogle, and there wasn't any cookie set.

What do they mean?

• It does not seem that iGoogle would be the "referer" to 20% of the visits to the Google home page.

• Perhaps 20% of the visits to the Google home page follow a link or are redirected to the iGoogle page.

• Perhaps a Google home page is the "referer" to 20% of the visits to iGoogle.

The main reason to go to the Google home page is to submit a google search.

The iGoogle page already has a Google search box. Going to the Google home page from the iGoogle page would be an unnecessary step that is more complicated.

Another reason to go to the Google home page might be to follow a link that is located there. Most of the links from the Google home page also seem to be on the iGoogle page.

If you clicked on the iGoogle link once, Google's homepage is iGoogle for you. Try to go to google.com and you're redirected to iGoogle. So for Google,

Google Homepage = Classic Homepage (80% visits) + iGoogle (20% visits)