Abstract
This paper addresses the issue of classification devices and their role in shaping markets. We depart from the notion that markets are shaped by multiple calculative agencies and examine how particular forms of calculation are made viable. Classification devices are the infrastructure that makes calculation possible and sustains particular economic orders. We illustrate these notions with an empirical, longitudinal study of a fuel retail company and its initiative to re-classify its network of petrol stations across Europe. Our study focuses on the extensive and protracted negotiations over what constituted relevant categories and the multiple perspectives involved in defining petrol station types. We illustrate how a store typology plays an important role in making assemblages of ideas (e.g. consumer-on-the-go), objects (e.g. store planograms), and managerial roles (e.g. category managers) coalesce around particular constellations of practices which impact upon the outline of markets.