Ultrasonic response is not something most devices are good at. We, unsurprisingly, tend to design your sound systems around what we can hear. Particularly when you are talking cheaper equipment the high frequency response of speakers and microphones is often not very impressive. There's also the issue that the digital audio compression we use for things, like TV broadcasts, deemphasizes high frequencies.
So for this to work they need:
1) A TV broadcast with sufficient audio bitrate to get their high frequency signal encoded (the AC-3 streams usually used in ATSC broadcasts can be any bitrate from 64kbps to 448kbps).
2) Encoded in such a way by the broadcaster that the high frequencies are preserved to a sufficient amount that their signal isn't distorted.
3) Reproduced by speakers good enough to produce their signal, but to do it at a sufficient level to be picked up (speakers roll off at more extreme frequencies).
4) Picked up by a microphone with sufficient range to be able to receive such a signal and isn't being occluded too much be being in a pocket or something.
5) Processed by a program running on the device, that has control of the microphone at the time the signal is playing.
Ya... While that isn't impossible, that is not likely to work any real amount of time. To have any good chance of working you'd probably have to push the signal down in to the audible range, which would of course piss people off to hear spurious high frequency noise. Likewise for it to be of any use the user would need to have an app on their device that is running. The mic doesn't magically record everything that comes in and store it for anything to access. A program has to be running and take control of the microphone to be able to get any input from it.
This sounds like an advertiser pipe dream, not something that has been tried with real technology in realistic settings.
People seem to think that ultrasonic communication is some kind of magic. It isn't. I mean it can be done, no question, you can encode information in sound, and you can do it in sound frequencies above human hearing. However that doesn't mean you can do it with any arbitrary device, or under arbitrary conditions.