there's externalities with ads. one is that the more ads i see, the harder i ignore them. i would expect consumer attention to work like roads, where charging more to use it is balanced out by the appeal of less traffic
it's not clear to me that an ad monopoly makes products cost more, even without getting into ads distracting the whole workforce
Not sure how it is these days, but back around y2k my buddy and I would hunt down Superbowl ads on the internet cause they were usually quite funny (and not aired here in Norway).