A few days ago Google announced your slice of the web. This seemed like an obvious move to do. I used to wonder about why a browser itself wouldn't have done this before. If someone knew all the sites someone was visiting, that was naturally the browser. Once again the browser industry lost this opportunity and once again Google took it with a toolbar that extends browser functionality to track visited sites.
Why is having users browsing history so important? Michael Wesch expresses it in a very artistically way in his video "The Machine is Us/ing Us", specially when we says: "Think of the 100 billion times per day humans click on a link ... teaching the machine":
Some practical uses of the web history that you can notice out there. When you search for something if there's a page within the results that you visited previously, it will show you something like '2 visits 7:52pm' or just the time of the last visit if you only visited once. I guess they'll switch to '4 hours ago' which is more user time friendly.
Now their searches that already were user sensitive if you had your personal history switched on, will become widely sensitive to all of your web logged navigation. It sure is powerful. Not to mention augmenting ad sensitivity and user targeting to a whole new level.
I believe this is huge. This is the personal memory of your web accesses, which is like being able to track back ... your thoughts!
On one side I love this functionality, in a sense I was missing it and waiting for it to be out there for my own use and convenience (my bad memory as always ;). But, on the other side, there is today only one company in the world that owns this information (obviously with user permission). Google was the first and only company that will be benefiting of the realization that clicks = metadata.
Of course it's adding to the feeling of great but scary ... as like Michael Welsh said, every click is teaching "The machine", the question now is: who is the machine????
update: it'd be nice to have a word cloud and some graphic stats