Ultimately it also suggests how incomplete the conquest of human attention was from the 1910s through 1960s, even after television had entered the home. For, though it had breached the private sphere, the domain of the interpersonal remained inviolate. In retrospect it was virgin territory for attention merchants, though before the home computer one couldn't conceive how this attention might be commercialized. Certainly no one had ever considered the possibility of advertising messages over the telephone—before one placed a call, for instance—not that the telephone was in need of a business model. And so, as AOL finally turned to the reselling of attention, it brought the commercial model of the attention merchant to one of the last spaces thought sacred—our personal relationships.

Tim Wu, The Attention Merchants, loc. 724