I don't think it does. How does the advertiser know what the spot on the site is worth without traffic estimates? See my response to chongli downthread: https://news.ycombinator.com/item?id=25431138
> Is it fraud if a real user "looks" at the ad but actually looks away from their screen? If they mute the sound? If they don't speak the language the ad is in?
None of these are fraud, because the ad is in front of a real user.
Fraud here doesn't mean "the ad doesn't perform as well as the advertiser hoped for some reason" it means "the ad was not actually shown to real users on the site, contrary to the agreement between the publisher and the advertiser".
Someone once told me how they got a bunch of cheap/used phones and just left them all running an app that shows ads. They'd glance at the phones now and then to see if they needed to "interact" with them to keep the ads rolling.
This seems like a problem with the current model of ads being paid for by impression/click, and switching to a model where ads are being paid for the time they're being displayed (pay X to have your ad appear here for Y time) the problem goes away.
Furthermore, the current advertiisng model also suffers from this problem even beyond malicious intent. Is it fraud if a real user "looks" at the ad but actually looks away from their screen? If they mute the sound? If they don't speak the language the ad is in? Etc.