His early career as a preacher may seem an incongruous footnote to the one that would make his name, but it is in fact quite significant if considered in the larger history of attention capture. Before the nineteenth century, human attention was a largely untapped resource in relation to its eventual commercial and political applications. One reason was the lack of advertising such as we would recognize it today. Yes, there have always been commercial notices and signs; the Greeks and Romans used them to indicate wares for sale, as did merchants in China. Some of the graffiti covering the walls of Pompeii, preserved by the eruption of Vesuvius, turn out to be advertisements for erotic services. But as we shall see, there is a crucial difference between this sort of signage and the industrialized capture of attention.

Tim Wu, The Attention Merchants, loc. 80