To sell that info. Duh. In order to trigger audio, your tv would have to be “always listening” so that it could respond when summoned. More than likely the “third party” in question are data collection agencies whose whole business is to track and marry IPs in order to create a seamless ad experience that’s targeted to users across multiple devices. These same companies determine whether a laptop and a mobile device are the same user using similar technology and then essentially sell masked access to that data to advertisers. The whole point from an advertiser perspective is to eliminate waste and only market to users who actually have interest in a product. Essentially, if I as an advertiser know that a user on a given home wifi visited my site, I can allocate my ad dollars to other devices that utilize the same home wifi. Why is it good for you as a consumer? Because smart advertisers shouldn’t barrage a users above an optimal frequency, so if you’ve already seen their commercial 3 times that day, they might intentionally not serve you their commercial a fourth time that day. And it means that the products you’re being marketed are actual products that you might use. So all male households shouldn’t get marketed tampons regardless of their media choices, unlike traditional TV where spot bookings are based on show demographics.