Interest based Advertising from Google

Got to repeat what I said previously:

I always had serious doubts that Google is going to track users in such a way, as Google is always looking for a way to collect users' info - Look at Youtube and all of other Google's acquisitions!

Specially after their acquisition of Urchin - currently known as Google Analytics.

In fact I was asking myself, when Google will use these huge data sets that it has about us?

The interest based advertising is something that I am working on (research), and I am trying to code algorithm that would understand users' interests...