The fundamental problem with this is that if I bought your product, it's because I was looking for your product after doing a decent amount of research which me

The fundamental problem with this is that if I bought your product, it's because I was looking for your product after doing a decent amount of research which meant I was on a bunch of retargeting lists and you've wasted money on me. I have never to my recollection purchased anything because of an ad. If I have clicked through an ad, it was simply because it was the quickest way to get to the website/product. There is a role for advertising because Google polluted their organic search results with Ads making it harder for you to find what you want and forcing you to compete for the top Ad spot. I realize that I can only speak for myself, but I have never seen any evidence that advertising works and I've worked in ad tech.