Its not magic, but spending on certain types of things do increase with GDP. Insisting that they don't, despite the evidence that they do historically because it is inconvenient for your argument isn't convincing.
> And similarly obviously classifieds didn't have even remotely near the same reach.
You are claiming that a classified in 1970 would not routinely reach tens of thousands of people?
> as opposed to graphical images, or even videos, imposed on people against their will
The nature of advertising has changes and I don't really doubt it has been made more harmful. What I don't see is a line between that and your fantastical claim that the internet is somehow a net negative.