Charles Herrold was the first radio broadcaster in the United States, broadcasting in 1909 at his technical college. By 1912 he was providing scheduled information and entertainment. Today commercial, public and community radio broadcasters are found supplying audio content to the public every hour of each day. For certain segments of the population, radio is the primary or only means of information and entertainment.

Commercial Radio

Commercial radio that operates as a business to earn profits is accessible in most areas of the world. Radio broadcasters sell small blocks of each listening hour to advertisers by agreeing to play advertising messages or commercials on the air. John R. Lott Jr., author of "Freedomnomics," notes that “advertising is a sensible way to finance radio broadcasting.” Commercial radio is the most well known of all broadcasting types operating on both AM and FM signals. Formats for commercial broadcasters vary greatly but are often based on specific music genres. Another primary format is talk radio, generally focused on sports or political and social issues, which provides what could be termed both information and entertainment. During the Great Depression, “the radio provided free entertainment in a period of economic hardship,” according to Duke University.

Public Radio

Public radio does not feature advertisements and is listener-supported. In the United States public radio receives private grants and government funding. National Public Radio (NPR) is the dominant public radio organization in the country. Formats focus on news, education, social issues and the arts while music programs are primarily jazz, opera and world music.

Community Radio

Community radio is broadcast media that is “independent, civil society based and which operate for social benefit and not for profit” according to Steve Buckley, President of the World Association for Community Radio Broadcasters. Community radio broadcasting has served to create and foster political and social change worldwide, including improving human rights and spreading democracy. “In almost all cases we find a correlation between the emergence of community radio and political change toward greater democracy.” Buckley further notes that community radio broadcasters are activists “who continue to operate in sometimes very dangerous conditions,” facing intimidation, physical violence and even death.

Passive and Active Listening

Listeners of each type of radio broadcasting either listen actively or passively. Music formats are best for passive listening, often to help pass the time while working, driving or engaged in other activities. Talk radio and educational programs require the attention of the listener and that he stay intellectually engaged. Both listening styles can be considered important to the listener, and may be used at different times.

Perceptions of Importance

“Personal importance is most closely associated with how (not necessarily how much) a person” listens to the radio according to David Giovannoni, a research analyst for the Corporation for Public Broadcasting (CPB). In his 1988 report, "The Personal Importance of Public Radio," Giovannoni states: “Since programming directly influences listeners’ use,” the perception of importance can be adjusted by providing programming that gets the listener to tune in more frequently. In the study that was the basis of the 1988 report, Giovannoni noted that “Ninety percent of the people who listen to public radio don't support it.” Even though 75 percent of those surveyed said that public radio is high quality, noncommercial, entertaining, informative and educational; less than half said that public radio was "important."