The initial definition of the forty clusters obviously involved considerable subjectivity on Robbin’s part, but from the beginning he expected the clusters to evolve and grow more precise. In his vision of America, traditional demarcations, like state lines, didn’t have much meaning; to drive across the nation was to visit not places like Kansas or Iowa, but rather local chapters of clusters like “Shotguns & Pickups,” “Gold Coasts,” and so on. While some (like “Sharecroppers” or “Industrial”) were found in only certain regions, in general the same neighborhoods, as he saw it, repeated across the land, with any local variations being merely cosmetic.

Tim Wu, The Attention Merchants, loc. 608