Or, when it's noticed a lull, and kmows you're influencable: Hire this personal trainer to get you back exercising!
Using heartrate, activity levels, mobilty can probably infer a broad picture of someones health, which of course, would be very valuable to health insurance/life assurance companies.
With this level of privatised surveilance, I'll stick with my mechanical automatic watch thanks.
Located in Hong Kong, elevated heart rate in the evening, spikes match tweets about police activity against protesters? Be prepared to be visited by the authorities.
google would sell "attention time to people whos heart rate spiked during the world series" but not tell the customers who those people were. you would be outing yourself if you click the ad.