Fundamental innovations in the basic provision and consumption of goods and services accompanied the radical transformation of artistic and intellectual life. After the First World War, modern business forms of credit, retail, and advertising helped sell increasing numbers of mass-produced goods — the products of a highly industrialized factory system — to ever-larger numbers of people. With the arrival of cinema and radio, commercial entertainment increasingly dominated the leisure time of ordinary people. The consumer revolution had roots in the prosperous decades before World War I and would not be fully consolidated until the 1950s and 1960s. Yet in the interwar years the outlines of a modern consumer society emerged with startling clarity.