Advertising has existed for thousands of years, starting with wall paintings in ancient Egypt and Rome used to promote goods and political ideas. In the 18th century, printed advertisements began appearing in newspapers to promote books and medicines. The development of radio in the 1920s led to the first radio advertisements, with early radio stations providing programming in exchange for brief promotions of sponsors. This model was later adopted for the new medium of television in the 1950s, establishing the ongoing practice of multiple short advertisements spaced throughout commercial programming.