When September arrived, and with it, Apple's new operating system, it was worse than the web publishers and advertisers could have imagined. Adblockers, overnight, became far and away the most popular of apps. Millions of copies were downloaded, turning what had been a trend into a torrent. By the end of the year, an estimated 100 to 200 million Americans were now using some kind of adblocker some of the time. Apple's plot, if such it was, had paid off masterfully.

Tim Wu, The Attention Merchants, loc. 1124