After World War I, the United States started converting from a wartime economy to a peacetime economy. In other words, the U.S. shifted from a producer-oriented nation to a consumerist nation, which means that the markets started to produce the items desired by the consumers. During World War I, Americans produced only what they needed with no surplus; however, expansion of the economy was encouraged after WWI. Transportation, industrialization, communication, and manufacturing advanced rapidly during the Roaring Twenties, contributing to the change. The forming of a consumerist economy was made possible by many factors, one of the most important was the advertising industry. The advertising industry promoted different products that appealed to the consumers and increased selling, and increased selling means more production, which led to the flourishing of the U.S. economy during the twenties. Moreover, starting from the twenties, more affordable goods became available for the consumers. Technological advancements, like washing machines, vacuums, refrigerators, irons, and radios , spread rapidly during the twenties, making life easier for American citizens and marking the twenties as a new era.