Hang on: ad placement is not based on page content but the viewers profile (constructed from search and browsing history, facilitated by tracking)
Right?
However, the servers were always crashing and I was always wondering when the customers would figure out that they were throwing money away.
Cookies and/or pixels - edit If you've opted out of being cookied, then you may be "targeted as an balding middle aged man with erectile dysfunction."
Also cause a lot of adtech is not sophisticated.
In terms of what ads to show you, AI not really necessary. Often it's just for stuff you've searched for on Google, amazon etc.