In this game of trackers and profile builders, as in so many others, Google and Facebook, de facto diarchs of the online attention merchants, reigned supreme. By design, both firms had acquired the best data on just about every consumer on earth, as well as possessing the best tools for collecting more of it, which by the 2010s both were prepared to exploit as far as possible. Never mind that each had originally been hesitant even to allow advertising to pollute its pages or interfere with the user experience. That was then. Since those years of initial hand-wringing, as investors and Wall Street demanded their quarterly increases in revenue, there was little choice but to turn up the heat, intensifying the reach of ads while hoping that their respective market positions were secure enough to prevent too many users from bolting. The essential bind of the attention merchant began tightening even on those Faustian geniuses who thought they had beaten the Devil.

Tim Wu, The Attention Merchants, loc. 1086