Uber discovered they’d been defrauded out of 2/3 of their ad spend
There was a freakonomics podcast recently about advertising (online and traditional).<p>No one can actually prove it has any ROI at all. No one is willing to run the experiments necessary. In the few cases of natural experiments, where ads got turned off for some people by accident, there was no change in buying behavior.<p><a href="https://freakonomics.com/podcast/advertising-part-1/" rel="nofollow">https://freakonomics.com/podcast/advertising-part-1/</a><p><a href="https://freakonomics.com/podcast/advertising-part-2/" rel="nofollow">https://freakonomics.com/podcast/advertising-part-2/</a>