Most people in the field don’t even ask themselves this question. They all have an incentive in believing it works.
There’s a book about it though: https://us.macmillan.com/books/9780374538651/subprimeattentioncrisis
Yeah it’s a good book. It’s a cycle that this issue surfaces every couple of years where someone does a study, finds that the numbers they’re given don’t match their own analysis and the ad tech platform does some PR to paper over the story.
Most people selling ads are just like the real estate agents in The Big Short. The media people make their money via rebate from the platforms by guaranteeing a certain volume of spend so they have no incentive to be putting hard questions to the platforms and the client is reliant on seeing the data which is provided by the platform with no third parties able to provide any level of transparency.
Money goes into Google, Amazon and Meta’s black boxes which spit out numbers. The agency people copy and paste the figures into a presentation and everyone congratulates each other for a job well done.
