I will either opt out of this or stop using Adsense, I think. I don’t particularly want Google to display ads to me based on the sites I have been visiting. OK, I buy books, but that doesn’t mean I want to see more advertising for them. And I visit a lot of sites based on what I happen to be translating. As for the effect on visitors to my site, it could be just as irrelevant to them, to say nothing of the invasion of privacy.