That's absolutely true. In particular, there's an interesting distorting effect caused by large-scale ad vendors and sites that want ad revenue. They always sh

That's absolutely true. In particular, there's an interesting distorting effect caused by large-scale ad vendors and sites that want ad revenue. They always show an ad, and the only question is which ad. While I think ads should just not exist (and people should universally block them), it would be an interestingly different world if the alternatives were "useful ad" versus "no ad".