> Knowing that you just visited Best Buy website 10 minutes ago and searched for a camera is _much_ more relevant to figure out which ad to show you on nytimes.com right now than the content of the article you're reading on nytimes.com

This sounds reasonable. But there is quite a way from that to the current implementation which seems to be along the lines of:

  if(male) { 
    showDumbDatingSiteAds();
  }

It doesn't take very many PhDs to come up with that, does it?