There's a variant called "header bidding" that got a bit of positive PR during an antitrust investigation of Google last year, e.g.: https://www.theregister.co

There's a variant called "header bidding" that got a bit of positive PR during an antitrust investigation of Google last year, e.g.: https://www.theregister.com/2022/03/11/cma_ec_blue_jedi/ https://www.theregister.com/2022/03/11/cma_ec_blue_jedi/ "The innovation of header bidding "promised to bypass Google's stranglehold on the exchange market," as detailed in a complaint filed in the US in a New York district court last year." But note that it's just a way to blast your personal info across even more ad networks! Privacy and "free and open market" are opposing forces here - the most private way to implement personalised ads is that all bids and targeting info is kept by a single ad exchange who matches and serves ads without sending personal info back to the advertisers. (Though not really because it's still strictly better to just block all personalized ads, of course.)