So, sell ads. Carve out a "your ad here" box somewhere in the layout, stick a hyperlinked jpeg in there, and charge a monthly rate or something. What's actually happened, is site operators get a line or two of 3rd-party javascript and treat it like a magic money button, with no idea (or care) what that mystery script actually does, then pile on a bunch of mystery "analytics" scripts, just to tell that site operator that nobody is clicking on the ads, or even really looking at them, or that user#x0fac45afedefab561259 searched for polonium tampons on some other site and lead condoms on another.
The rest of out here got sick of scripts loading other scripts loading other scripts loading other scripts, popups spawning popups, annoying autoplay videos that move over to the corner and stay there, overlays with tiny-x close buttons that may not even work, and all the goddamn surveillance attached. So, we've shut all that shit down, and the willful ignorance of blindly trusting some-odd ad network (or usually several at once) has bit website revenue right in the ass.
When I enter gamefaqs.gamespot.com in my browser, I'm intending to look at content from gamefaqs.gamepsot.com, not evidon.com, cbsinteractive.com, qualtrics.com, demdex.net, taboola.com, agkn.com, moatads.com, criteo.com, indexww.com, adsrvr.org, sharethrough.com, scorecardressearch.com, doubleclick.net, adnxs.com, rubiconproject.com, casalemdia.com, fastly.net, advertising.com, adsafeprotected.com, 2mdn.net, truste.com, googletagservices.com, iasds01.com, trustx.org, serving-sys.com, trustarc.com, or whatever the hell else domains any of those decide to forcibly insert into the DOM.
What the fuck is wrong with your website when you're loading scripts from twenty-eight domains, and trying to set cookies for twenty-four domains? Bullshit like that is why people block ads and install privacy plugins, almost reflexively nowadays, and increasing in numbers all the time.