This site has a graph that say 55% of visitors to gaming sites use adblock http://contently.com/strategist/2015/07/10/why-adblockers-sh... . I would assume hacker news visitors would have a similar number. That would be an interesting thing to measure. Someone who gets to the front page of HN should measure what percent of people with a HN referer block ads.
And many ads are paid per view, not per click.