Even the most successful and adaptive efforts to harvest attention can come up short. In fact, by the nature of the crop, most do. Ultimately the military would have to resort to conscription to meet its manpower needs. Still, Kitchener’s recruitment drive was almost certainly the most successful in history. Out of 5.5 million men of military age at the start of the war, about half had enlisted voluntarily by late September of 1915, this despite staggeringly high casualties in the early years. To heed the call was to accept a great chance of death or serious injury, a roughly 50/50 chance. That Lord Kitchener’s campaign managed to achieve by persuasion what other countries achieved by legal coercion was a lesson lost on no one. Just as the patent medicine advertisements had demonstrated that attention could be converted into cash, the first propaganda drives showed it was also convertible into other forms of value, like compliant service even unto death. The British example would come to be copied by others for the rest of the century: by governments in the Soviet Union, communist China, and Nazi Germany; and elsewhere, as we’ll see, by commercial actors. As the historians M. L. Sanders and Philip Taylor wrote, “The British Government was responsible for opening a Pandoran box which unleashed the weapon of propaganda upon the modern world.”

Tim Wu, The Attention Merchants, loc. 147