This sounds like an optional feature no different then the meatporical sales person remembering what you've bought in the past and making suggestions about what to buy next.
Except this salesman wants to know about my whole life so he can make suggestions for my whole life. Aren't you a bit worried about all that data being stored by a company?

Is every one here so parinoid that they think that google's perpose is to gather data on you?
Um, google said they want to.

For those who think so my question is why? Why would google want to or bother to go through all this trouble and then what would they do once they have all this data?
So they can carry out their stated goal of being able to tell you what to do tomorrow or what job to take.

CR