> I'm still surprised no one has yet figured out a way to store sensitive data about personal interests and preferences on the client-side I'm pretty sure iAd

> I'm still surprised no one has yet figured out a way to store sensitive data about personal interests and preferences on the client-side I'm pretty sure iAd works like this no? Also it wouldn't be massive advantage, you'd be serving less relevant ads (so losing out to competitors) and you can still track which ads a device requests.