The same way they did in the past, with broadcast radio and television: they base it on audience numbers rather than tracking whether people actually listened or viewed the ad. Besides, isn't one of the major motivators of tracking to avoid fraud? (Which I find ironic, given I don't view advertisers as very ethical in the first place.)
> Either way I fundamentally disagree with them on the idea that push advertising is ethical in the first place
The way I think of it: advertising doesn't have to be unethical, but it incentivizes unethical behaviour.
> Like did you also not fast-forward your VCR through ads in those days and instead dutifully watch attentively lest God know you were naughty?
I would typically walk away to do something else. Same outcome though. That said, I started to turn away from broadcast media in the early to mid-1990's. I forget whether it was due to advertising, but the end result was a lot less exposure to advertising. Which is a good thing IMHO.