Well they also infest the client side since they likely developed the main part of your web browser, so they can still know there’s a black cover in the DOM.
If the ad is just blacked over, it is still loaded, and they wouldn’t know.
If it became a common thing, they’d have to add detection for it. Not necessarily to stop people doing it, but to ensure advertisers aren’t charged for invalid impressions. Practically every major ad network has adblocking detection; they just don’t always make it obvious (e.g. they might silently log it).
They can only tell that something is blocked because the ad wasn’t loaded from a server. If it’s not loaded, then they can’t count it as “viewed.”
If the ad is just blacked over, it is still loaded, and they wouldn’t know.
Well they also infest the client side since they likely developed the main part of your web browser, so they can still know there’s a black cover in the DOM.
If it became a common thing, they’d have to add detection for it. Not necessarily to stop people doing it, but to ensure advertisers aren’t charged for invalid impressions. Practically every major ad network has adblocking detection; they just don’t always make it obvious (e.g. they might silently log it).
If they were effectively able to detect it they would be able to block you watching the rest of the video.