It's disconcerting that, literally knowing everything about you, puts advertisers in a position to accurately target you in insidious ways.
Advertising is incredibly good at convincing people that they need [product] as it is. Assuming the 'rational actor' theory ever treaded water, this sinks it.
It does seem like the logical progression for Google and friends. What will be interesting is how such invasive monitoring will be pitched as innocuous. People seem to be a-okay with corporations mining their data, though.