I slightly disagree that “producing most of what there is to read requires money”. Yes most writing is made for profit, but the very best writing I is often made because the author needs to say it, not because they expect compensation. Definitely need to look at evidence on this, though.
If bad writing is helped more than good writing by ad revenue, then it’s less clear that advertising is good.
If observers are distributed with constant density in 3d space, then adding 3 extra bits to the position of a camera covers 8x the volume, and thus 8x the observers, so the scaling is the same as if you were just numbering the people