Across this and the other[0] highly active digital ads post, there's 3 interesting forces at play:
a) technologists screaming "ads are literally the worst societal cost, like ever" who don't want to understand the industry
b) advertising folks taking up arms to defend their shamanistic, money-printing machines without statistics (Reason No. 7 will SHOCK you)
c) A tiny, tiny group of Mandalorian-like voices who have a necessary statistics AND industry understanding who are being drowned out
(this is in jest, but I double-dare you to say it isn't at least directionally accurate)
Other commenters have mentioned it throughout this whole comment thread as "incrementality tests". Amongst other approaches, this is the way.
Freakonomics severely lack the industry understanding. Listening to the podcast was like hearing how HTML is a programming language from the kid in week 2 at code camp. Then too the article, all the issues with Uber was just doing a bad job of managing their ad spend and they can fall into group B, noted above.
The baseline of this work is a control group who see no ads and then you build your tests from there that factor in channels, cohorting, and other components to get a statistically significant outcome. Yes, this will get more challenging with upcoming privacy changes (IDFA removal, et al). However, the last 10 years this wasn't a problem and I'm sure the corporations in the identity resolution business will hand-shake on a bunch of 2nd party data deals that just move the deals done in broad daylight around identity tracking and audience creation to the alley. Further, any advertising that is tied to an already known customer is able to be backed into at an audience level with login and cookie data. Even Pi-hole users may not be exempt here.
To finish with some constructive advice:
1) Advertising is not a synonym for marketing. We're only talking about advertising in both HN threads.
2) Every industry has high and low quality. Pareto's principle should be aggressively applied to where one spends their budget in the cesspool that is the Internet.
3) If you're ever seeking an agency to provide advertising services and they don't have a qualified data science or statistics leader (10+ years work experience, degree in Stats/Math/Econ, an MBA, or similar), run. Run from those shiny-shoes gurus. Channel your inner Usain Bolt and run.
0. https://news.ycombinator.com/item?id=25620707