[ncmncm]

We may take as given that advertising agents cannot simply buy the history of your usage, outright.

Does that mean much? Google would not be so foolish as to hand over everything at once, when they could do something else that allows them to sell it, or the use of it, again and again. They doubtless have a hundred ways, each more clever than the last, to sell it again and again. Since they control the whole apparatus, they can make full use of all your history at all times without revealing to advertisers anything that would allow Google to be bypassed next time.

So, Google's pledge is simply that every use of your data will necessarily involve paying Google again. And, anything at all that can help Google uniquely identify you with activity anywhere online certainly is collected into your file, the use of to be dold for what the traffic will bear.

Your ISP has a different set of incentives.

[dodobirdlord]

I don’t think this addresses any of the three points, unless you’re interpreting the OP’s “advertisers, gov agencies and corporations can freely purchase your search history from Google” in an entirely non-literal sense that has nothing to do with the literal meaning of the words.

> Your ISP has a different set of incentives.

Indeed, ISPs are known to wholesale sell their user’s traffic history.