Final answer:
1920's advertising was strongly influenced by the propaganda campaigns of the U.S. government during World War I, particularly through the use of radio, which became a key medium for reaching consumers. These strategies shifted post-war advertising from focusing on patriotism to consumer goods and a life of luxury, reflecting the era's growing optimism and prosperity.
Step-by-step explanation:
The success of a WWI era agency had a profound influence on 1920's advertising. The agency in question was the United States' government's propaganda organization. Its massive advertising and public relations campaigns during World War I used media to encourage people to support the war effort. This set a precedent for the expansive use of mass media for advertising in the subsequent decade.
Radio became the revolutionary medium in the 1920s, as it had the power to reach consumers in innovative ways without requiring their active participation. Advertisers could easily influence both the audiences physically close to a radio and those who held shared social attitudes. Following WWI, this new approach was adopted for commercial advertising, shifting the focus from selling war bonds and patriotism to selling consumer goods and lifestyles.
By the 1920s, with increased optimism and economic prosperity, advertising campaigns began to sell products that symbolized opportunity and the good life. These campaigns were built on the foundations of wartime propaganda techniques, showcasing how effective targeted messaging could be on a national scale. The era was marked by a shift from necessities to luxuries, from restraint to consumerism, guided by the powerful influence of advertising.