Where to start?

What makes you think that they reduced their spend by 99%? They simply limited their campaigns' targeting to a whitelist of 400 sites, there's not any indication that they were spending equal $ per placement.

I'm not sure why you believe that aggregating statistics is some sort of lie -- in AdWords, advertisers are able to easily see the placement for each one of their clicks. It's not some big secret hidden from advertisers.

You are also confusing why and how much advertisers care about the content of the sites. The site's content is only one signal as to the quality of an impression. It's a proxy for quality, because it's a good indication that a particular user might find the ad interesting and relevant. It's not as good of a signal as the characteristics of the user. Why would Chase be interested in only advertising on "banking" sites anyway? It's pretty silly to think that it's somehow a big scandal if the website content isn't directly connected to the business of the advertiser. Advertisers definitely don't want that. What they want is a quality user -- Chase wants someone who is actively shopping for banking services to see their ad everywhere, but they don't want to waste an impression on someone who isn't. If I were guessing, they were likely aggressively remarketing on the entire network, and now they're restricting to sites. In other words, they were following users across the entire internet, wherever they could find inventory, and now they'll just follow them to the most popular sites.

You're conflating two issues -- brand safety and ad spam. The first is the relevant issue: "I don't care how good the user is, I can't have the NYT printing that my brand name showed up next to a terrorist recruitment video."

You're talking about ad spam, or "you charged me for this click but it was fraud from the publisher." That's not at all what the story is about. You're jumping to a conclusion that the now excluded websites were fradulent to begin with. Do you find it unbelievable that there might be 400,000 legitimate websites in the set of available placements for Chase's ads, without spam? Why?

You are mixing terms, Adwords isn't an exchange -- AdWords has inventory from owned-and-operated sites (Google, YouTube) and network partners (AdSense, AdMob, Google Display Network, etc.) AdWords doesn't sell any inventory from ad exchanges, it has its own network, particularly because it wants to maintain the quality of the placements. Spam is actively and aggressively policed.

Again, that's not what the article is about -- none of the big tech co's have been doing much to prevent ads from showing against certain types of offensive content -- especially content like hate speech, fake news, etc., because it's really difficult to identify correctly at scale. The media and advertisers have started caring because it's the cultural moment we're in right now, I guess.

Finally, it's not the case that "garbage inventory" is spread around, subsidized by the good stuff, in a money making scheme. Such a scheme wouldn't make sense anyway. High-spending, sophisticated advertisers know the conversion rate of the advertising, and they have a sense of the return on ad spend that they'd like. Cost-per-click is just a shallow metric in the market, if the real value wasn't there then demand would decrease.

Does the industry advertise until they break even? Of course, that's the market dynamics, and it's economically rational. Advertisers should, and do, spend up to the breakeven point (or the discounted lifetime value of the new customer acquisition). They do so because one should accept growing one's business by a marginal customer even if it's a breakeven proposition.

That's not to say that advertisers don't reap value from advertising, of course they do in reality (or at least, they always try to). I'm just pointing out that click auctions are expensive because the competition is willing to spend -- not because you're subsidizing spam.