Because the most active and knowledgeable users on the internet all use ad block that means that they will visit sites that are absolute aids and have no clue. This also means that they will share links to those sites with no idea they are sending traffic to an ad filled site. I happen to be on a computer that I haven't put ad block on yet and some of these sites are ridiculous. There is no way anyone would continue to use them verses alternatives if it weren't for the volume of ad block users giving them relevance, sharing links, uploading content, and referring people to that site when it comes up in conversation. Because (estimating) 1/5 of the traffic is not ad blocked (ad block people are probably around two thirds of the population but also use the internet much more), they still get to show their hail storm of ads to somebody. So if you ever build a site that's going to have ads on it, if you are thinking about blocking ad blockers, reconsider it. There's a reason most sites are smart enough to not block ad blockers even though any site's developer can research how to do it pretty easily.