But how would that serve ads to the eyeballs? You forget that most of modern webcontent is just packaging fluff for eyeballs to more easily digest the real content payload - the advertisments.
That's not my problem. If it were, I'd solve it by embedding ads in the video stream itself, which is how traditional video broadcasters have done it for more than half a century. In the audio realm, Pandora already does this with third-party clients perfectly fine.