Comment by GeneralMayhem
7 hours ago
Google's AdSpam/fraud/bot-prevention team was, when I worked there, world class and fairly well funded, took their job seriously, and had access to all the data. It's an existential threat to the ad business, because if Google gets a reputation for being full of bots/spam, then the advertisers will bid lower per click/conversion to compensate, which means that legitimate website publishers will get paid less and go to other networks, which is a feedback loop that leads to the entire market collapsing (see also: https://en.wikipedia.org/wiki/The_Market_for_Lemons). It's absolutely worth refunding/zero-rating huge amounts of advertiser spend to avoid that situation, and they do.
It's not that they're not trying, it's just a very hard problem.
Fair, I retract my cynical conjecture
Problem 1: Buyers cannot tell if a product is good or bad, so they offer less money and good sellers may leave.
Suppose 50% of used laptops are good and worth $1,000, while 50% are bad and worth $400. Since you cannot tell which one you are buying, the average value is 0.5x1000 + 0.5x400 = $700, so you will not want to pay more than about $700.
But owners of good laptops may refuse to sell for $700, so more good laptops leave the market and the chance of buying a bad one increases. And the only guy selling for $700 is the lemons.
Problem 2: The theory assumes buyers already know how many bad products are in the market, but in real life they often do not.
Its obvious this market for lemons can’t be true
Just to be clear, this is different to the problem of Google ads that link to malware and fake banking websites and promotion of cryptocurrency scams isn't it?