Serious question: is a person always the same on every site? Can they be reached with the same message in different contexts? The argument for targeting says yes, but then why is porn ignored? Real people, doing, ahem, real things for significant time, but no advertiser (as a rounding error on total advertising spend worldwide) wants to advertise on porn sites.

I think a message's context matters - and this is almost self evident from examples like ads for airline tickets being shown on plane crash articles. I think targeting is great, I really do, but I think the value of trusted brands is likely just as, if not more, strong.

If context matters, and I think that argument was the entrenched idea pre-internet and has not been disproven, then where is the positioning of targeting? My hypothesis would be that targeting is likely best utilised when people stray from self selecting brands, e.g. NYTimes needs no targeting, but a smaller publication likely does, as people aren't there for the brand's known positioning, but because of their targetable interests, e.g. they ended up on a site about coding, or computer games, or knitting or whatever.