Why Google does Talk ?

Why does Google provides a instant messanger with a peer to peer voice messaging? In this post I argue that in fact they are doing a kind of automating social tagging in order to improve their search results.

In a reaction There goes Philosophy point #2 on a slashdot posting, it was mentioned that Google better updates their "10 things":
Google does search. Google does not do horoscopes, financial advice or chat.
since the release of Google Talk that is a chat program.
And they did (see the full disclosure at the bottom of the page)
I started wondering why Google does talk. In my opinion they provide the VOIP/chat program just because this is sensible service to their users. Hence users will use it. As a consequence Google can get a good grip on your dailly social network. This is what they are after in my opinion. Because if they know what you and your friends at Google Talk/Mail are searching, they can improve their Page Rank search results by making use of your social network structure. Just like their Page Rank algorithm, a spin-off of the founders mathematical journey in the graph structures of internet content, makes use of the link structure of the items that GoogleBots indexes. In fact they can automate a kind of social tagging. That Google can record what you search was already remarked earlier at Google stealthily monitoring clickthroughs from search-results

I think it's a good value proposition. Google Talk for free, simple, no bypass of the corporate firewall with file upload (this is why Skype was considered insecure by Gartner), small screen estate and in the end better search results. Just like your Gmail inbox is read by machine programs, the social network is build by programs. Privacy is relative maintained as long as Google wants it. Unfortunately, history learns that if it can be revealed it will be revealed.....