Seeing the necessity to keep innovating, the government did have a few more inspired ideas. For example, it built a small fleet of specialized “cine-motor vans,” which were equipped to screen films conducive to enlistment on large walls around the country—the drive-in movie was thus born not of romance but existential threat. In 1918, on the fourth anniversary of the war, the government would distribute a special, sealed message from the prime minister to be read aloud at 9 p.m. sharp at more than four thousand cinemas, music halls, and theaters. By such means—at a time when “broadcast” still referred to a crop sowing technique—the prime minister reached an estimated 2.5 million people at once, an unheard of audience at the time.

Tim Wu, The Attention Merchants, loc. 145