Very simplified TLDR: you visit a news site. They load an ad network and tell it “put ads here, here and here”.
The ad network now tells 300 companies (seriously, look at the details of some cookie consent dialogs) that you visited that news site so they can bid for the right to shove an ad in your face.
One of them goes “I know this guy, they’re an easy mark for scams according to my tracking, I’ll pay you 0.3 cents to shove this ad in their face”. Someone else yells “I know this guy, he looked at toasters last week, I want to pay 0.2 cents to show him toaster ads just in case he hasn’t bought one yet.”
The others bid less, so that scam ad gets shoved in your face.
How online ads actually work.
Very simplified TLDR: you visit a news site. They load an ad network and tell it “put ads here, here and here”.
The ad network now tells 300 companies (seriously, look at the details of some cookie consent dialogs) that you visited that news site so they can bid for the right to shove an ad in your face.
One of them goes “I know this guy, they’re an easy mark for scams according to my tracking, I’ll pay you 0.3 cents to shove this ad in their face”. Someone else yells “I know this guy, he looked at toasters last week, I want to pay 0.2 cents to show him toaster ads just in case he hasn’t bought one yet.”
The others bid less, so that scam ad gets shoved in your face.
That’s extremely simplified of course. https://en.wikipedia.org/wiki/Real-time_bidding has a bit more of an explanation.
::hugs my PiHole::
It’s a good start but you absolutely want in-browser ad blockers too. Not all crap is served from dedicated garbage serving hostnames.