Much of the internet runs on ads; but maybe it's a house of cards. Apps, web pages, other content-thingies show ads to defray their costs. Advertisers want to show their messages to potential customers, and pay to do so. Everybody wins.
Except it doesn't always work so smoothly. A small business might want to show their ads on news sites and phone games and Google searches and other places; but maybe doesn't want to keep track of how their ads are doing at all those different places. So maybe the small business signs up with a couple of intermediary services, each service promising to show the ad to some desired demographic. Maybe everything's working fine? Maybe it's not? It's hard to tell.
The small business starts getting billed for ads. Thanks to creepy surveillance, that phone game thinks it knows its players' demographics, and thus will show the ad to the right people. But what if it has the demographics wrong? Or what if the intermediary service messed up and asked for the wrong demographic? Or what if the intermediary service is crooked, never actually places any ads, just sends a plausible-looking bill? Or what if…
It turns out, a lot of this stuff is pretty opaque. Publishers and advertisers have to take a lot on faith. We know ads aren't always shown to the right people, but we don't know how often. We know there's fraud out there, but we don't know how much.
The book's author compares the situation to the subprime mortgage meltdown: We know there are some bad assets out there. We know the rating system has incentive to be lazy about seeking out that badness. Is it all about to fall apart? Maybe. That could be darned bad news for news sites; even if the advertising markets only crash for a short while, it might be long enough for shoestring news organizations to go under.
