If what you're talking about is the source of the ad, why did you see the ad yourself? Were you shouting about ear wax removal at your phone?
There are millions of ways the adware running on your phones could've correlated your profile and spread the "infection" to your friend. Basic location access being the most important one, but sharing an IP address (your friends' WiFi?), being near the same Bluetooth beacons, having the same stored SSIDs, or mere coincidence that your friend saw the same ad targeting a wide demographic are much more probable than "my phone is listening 24/7".
Sure. But its fun, and we can always replicate, just need a terrible ad.
Do note, this was tested in a park, so no shared WiFi, no Bluetooth beacons/devices. Also, this ad doesn’t/didn’t show up for others, ever.
I’m assuming like most friends you and your friends have nothing in common like interests, demographics, etc.?
And I’m assuming you also made them aware of other ads you’d seen recently so they could see if those showed up as well?
Yep. They 100% do not share an interest in ear wax removal, or had a medical need of that nature.
Why do you think I would put up a comment on HN of all places, with this degree of confidence.
> tested with other ads… If I knew that this, was going to be needed to study, 5 years into the future, I would have conducted a double blind study. Sadly I could not, however, it’s still fun, so we can always replicate.
The question is, have you found a horrid ad yet? Side note, this was in the UK