The automation of customized advertising was intended, in theory, to present you with things more likely to seize your attention and make you click. It must be seen as a continuation of the search we have described for advertising’s Holy Grail: pitches so aptly keyed to one’s interests that they would be as welcome as morning sunshine. The idealists foresaw a day when ad platforms would be like a loyal valet who detected his master’s needs before he was aware of them, who suggested a new pair of shoes as a reasonably priced replacement for those you hadn’t noticed were wearing out. Perhaps he would remind you of your mother-in-law’s birthday while offering to send an appropriate gift at a one-day discount.

Tim Wu, The Attention Merchants, loc. 1080