Question

If the Google Analytics cookies are removed from the web browser, how GA tracks that if it was the same computer from where a site having GA.js code was accessed?

for instance, http://www.stackoverflow.com has GA.js code to track it’s visitors. A user opened it in his/her browser and GA starts tracking the traffic, but the next hour all of the browser cookies are removed.
NOW, how GA will track the same user accessed this site before?

Answer 1

*This cookie is typically written to the browser upon the first visit to your site from that web browser. If the cookie has been deleted by the browser operator, and the browser subsequently visits your site, a new __utma cookie is written with a different unique ID. This cookie is used to determine unique visitors to your site and it is updated with each page view. Additionally, this cookie is provided with a unique ID that Google Analytics uses to ensure both the validity and accessibility of the cookie as an extra security measure.* – Google: http://code.google.com/apis/analytics/docs/concepts/gaConceptsCookies.html

So it doesn’t track them as the same user.

If you’re very interested, I recommend their “Conversion University” videos: http://www.google.com/support/conversionuniversity/bin/request.py?hl=en&contact_type=indexSplash&rd=1

If you really wanted, you could cross reference an ip number with a browser fingerprint, and have a pretty good lock on a browser / location combination as a result. However, there are two reasons most people won’t bother:

1. It’s a big pain in the bum
2. It doesn’t give users the option of not being tracked, which they might not like, and it might not even be legal, depending on privacy laws which constantly change with technology.