John b. Dunham Pianos Testimonials from several musicians Harper's Weekly, December 31, 1864

The situation radically changed in the 20th century, the heyday of legal regulations in advertising, a process that the U.S.A. was very influential in.

Advertising agencies today are highly specialized companies which employ a large number of people in a variety of business and creative skills, including advertising and marketing specialists, designers, copy writers, artists, economists, psychologists, researchers, media analysts, product testers, librarians, accountants, bookkeepers, and mathematicians. This business sector makes billions of dollars each year, depending on the economical growth and development of a country but also enhancing exactly this.

The agencies make money in different ways, buying time for an ad on radio or television for a customer or space for an ad in a newspaper of magazine. They always keep up to 15% of the cost as a commission, which has become a standard in the advertising industry and covers a huge part of the agency’s income. Of course, the range of offers of an agency is much bigger than simply providing space or time for ads on TV, radio, newspapers or magazines. They offer their customers whole packages of approaches for a specific population group.

The first radio-advertisement was broadcast in 1922 in New York on the WEAF radio station.

Thus in the 1920s advertisers and their agents had come to realize radio's possibilities. With its drama and immediacy, radio could convey their message directly to the consumer who would not need to purchase a publication or even need to be literate.

In the 1950s television was introduced and quickly developed into THE advertising-media. In the 1950’s common income from the advertising industry rose to $ 10 billion a year. In 1980’s this index was $ 100 billion! Now advertisers could demonstrate the use of their products and present well-known figures to praise it. They could also affect emotions through television.

Today advertisers spend millions of dollars for their campaigns, although they don't always know how effective their advertising dollars really are.