Think "product placement" instead of "position placement".

Generation 1: You're searching on a keyword or a web page has a keyword and advertisers who have bid on that keyword place ads on that page. Search for "car" or go to a car related website and you see Ford ads.

Generation 2: Information about you is being tracked such that a profile gets created suggesting you'd be a match for a product that an advertiser is willing to pay to show an ad for. Chat about wanting to buy a new car and see Ford ads across any website you visit.

Generation 3: Same as above, but now as you seek out content, that content is being customized for you around that advertiser's product.

Remember when CNET got busted recently for AI generated articles? Imagine if every user got the article written slightly differently around products based on the collected data of a user profile.

So now an article about the transition to electric vehicles is focused on the new electric Ford Mustang as opposed to the Tesla, because there's enough profile information on you to customize the article that way.