> As a viewer of ridiculous ad placements, and as a frustrated buyer of online ads, I continue to conclude That adtech Is largely snake oil. In fact, I encourage you to look into the well-founded claims and research which call into question the very activity of marketing as a whole.

At least from my own anecdotal observations (including conversations with confused less technical friends and relatives started by questions like "how does this website know enough about me to show me that ad?"), the issue to me seems less that ad tech doesn't ever produce relevant ads, but that in practice very few people actually click ads, much less buy things from the destination, regardless of whether the ads are relevant or not. If anything, seeing a well-targeted ad often makes people feel creeped out, and their reaction isn't to go "oooh yes, that's perfect for me, let me click it", but to immediately close the browser tab and maybe even avoid the website that showed it to them in the future (because it's not obvious to a lay user that the ads are usually sourced from another party rather than the website itself). Slightly more tech-savvy users might even be aware of how ads are sometimes a vector for malware and avoid clicking them because the risk of getting something nasty isn't worth the probably quite low reward of buying something they could probably find just as easily on their own by actively looking. In practice, I have to wonder if it even matters whether adtech is effective at targeting or not, because I'm skeptical that the way people interact with ads ever would generate enough revenue to be worth it.