Personalized advertising has one key property that is very useful to this generation of Internet companies: it moves the ad dollars away from websites selling ads (aka "publishers") and to the networks (Google/Facebook).
If you're, say, the NYT, you can sell ads, of course. But anyone who wants to buy ads on NYT can instead buy ads on other websites that only target NYT readers. Which are much cheaper.
This is why news organizations all went paywall a decade ago. When you had to buy ads on a website to advertise to that website's audience, news was rolling in money. That's why they gave everything away for free, it'd be really dumb not to. But then Google and Facebook pirated[0] their audience, meaning all that free website traffic from the search engines is completely meaningless and provides no revenue.
[0] Piracy as in "stole our lunch money", not piracy as in copyright infringement. We're making a moral judgment, not a legal one.
Are they? According to whom and compared to what --- the ad networks themselves? They control everything about this game.
It's possible for someone with deep pockets to build an ad network that operates in a similar manner and offers pretty much everything Google and Facebook do minus the privacy invasion crap.
The only essential difference being how the ads are targeted. Instead of targeting individuals, the web content they are looking at would become the target --- based on the blatantly obvious "metric" that the individual must have at least some interest in what they're looking at.
This should actually be easier/cheaper to implement and maintain (no personalized metrics) and thus the ads should be less expensive. The main reason this doesn't exist in a more popular form --- Google/Facebook have sold advertisers a big load of their own marketing hype and used this to effectively monopolize the market.
If you're, say, the NYT, you can sell ads, of course. But anyone who wants to buy ads on NYT can instead buy ads on other websites that only target NYT readers. Which are much cheaper.
This is why news organizations all went paywall a decade ago. When you had to buy ads on a website to advertise to that website's audience, news was rolling in money. That's why they gave everything away for free, it'd be really dumb not to. But then Google and Facebook pirated[0] their audience, meaning all that free website traffic from the search engines is completely meaningless and provides no revenue.
[0] Piracy as in "stole our lunch money", not piracy as in copyright infringement. We're making a moral judgment, not a legal one.