Totally agree with you. I think also that it's very possible that delivering-adverts-with-minimal-privacy-infringement is a different class of problem to just "

Totally agree with you. I think also that it's very possible that delivering-adverts-with-minimal-privacy-infringement is a different class of problem to just "delivering-adverts". Maybe it's a type of problem where profit can only be extracted by means of huge economies of scale and well-staffed teams of ML experts? Like deep-sea oil drilling versus drilling in the desert?