Joe_F wrote: Who, precisely, is worse off if the people who do not want to see ads do not see them -- and in what way, and why?

The website owner is worse off financially. With Google Adsense, which Mudcat uses, the site owner is paid per click, or per thousand times the ad is displayed - I don't know which. If everybody blocked the ads the site would get no income. Google would get no income from the site either. Google auctions spaces on each site, so if a site has few users, or less affluent or desirable users, or a low rate of 'click-through', then the ads will be cheaper and the site-owner (and Google) will get less income.

The main advantage of Google Adsense for website owners (as I understand it, not running an advertising website myself) is that it's easy to set up. You include the scripts on your webpages and leave the rest to Google. Great if running a website is not your main job or interest.

The main disadvantage is that you have little (and apparantly now less) control over what ads people see and where they appear. Users' experience of your site will vary according to what device they use and - because Google sells ads based on tracking - according to web history, gender, political affiliation... The result is often horrible to look at. And very slow.

So more and more people block ads. Firefox now blocks tracking scripts by default on desktop and mobile (including iOS) - which kills most ads on Mudcat. Apple, which for years didn't allow apps that interfered with web access, now allow limited ad-blockers. So, apart from on old machines and inadequate browsers, viewing ads is voluntary. And there's a war going in between ad-publishers and ad-blockers - one result of which is the 'We see you're blocking adverts!' warnings but also ever more complicated tricks to get the ads past the blockers, which slow sites even more.

A few years ago AdBlock Plus, which was the original and then still the main ad-blocker, introduced Acceptable Ads. They were (and still are) much criticised for it - accused of betraying users and selling out. But I thought it was a good idea. I suspect that if Mudcat's ads were 'acceptable' according to that policy nobody would complain and I for one would not block them. I don't know what happened to acceptable ads, but it didn't catch on.

So what will non-commercial sites like Mudcat, and the many small 'hobby' websites which use ads to pay for their servers, do when everybody blocks their ads? There are alternatives to Google Adsense, and some might be less-intrusive, but AFAIK there are none which don't track users. You can sell and host your own adverts but I expect that's a lot of work. (Maybe someone could offer a feed of 'acceptable' folk/blues/whatever-related adverts.) So most sites will probably stick with Adsense, irritate their users, drive some of them away, and see their income dwindle.