Tim Hwang’s 2020 book, “Subprime Attention Crisis,” argues targeted advertising is a bubble set to burst. He argues that the intricacies of programmatic and the perverse incentives of agencies and ad tech platforms to maintain a steady flow of ad dollars have created a persistent opacity in programmatic markets.  Therefore he says it’s only a matter of time before the bubble bursts and advertisers pick up their toys and go home. The result will be a collapse of programmatic ad spending and a partial collapse of the free internet.