In the United States a public service announcement(PSA) is defined by the Federal Communications Commission (FCC) in a formal and detailed manner. A PSA is "any announcement (including network) for which no charge is made and which promotes programs, activities, or services of federal, state, or local governments (e.g., recruiting, sale of bonds, etc.) or the programs, activities or services of non-profit organizations (e.g., United Way, Red Cross blood donations, etc.) and other announcements regarded as serving community interests, excluding time signals, routine weather announcements and promotional announcements."

PSAs came into being with the entry of the United States into World War II. Radio broadcasters and advertising agencies offered their skills and facilities toward the war effort and established the War Advertising Council which became the official homefront propaganda arm of the Office of War Information. Print, outdoor advertising and especially radio became the carriers of such messages as "Loose lips sink ships," "Keep 'em Rolling" and a variety of exhortations to buy War Bonds.

By the end of the war, the practice of volunteering free air time had become institutionalized as had the renamed Advertising Council, which now served as a facilitating agency and clearing house for nationwide campaigns which soon became a familiar part of daily life. "Smokey the Bear" was invented by the Ad Council to personify its "Only You Can Prevent Forest Fires" campaign; "A Mind Is a Terrible Thing to Waste" raised millions for the United Negro College Fund; the American Cancer Society's "Fight Cancer with a Checkup and a Check" raised public awareness as well as funds for research and patient services.

The ultimate demonstration of the effectiveness of public service announcements came in 1969. Two years earlier, a federal court upheld the FCC's application of the Fairness Doctrine to cigarette advertising on radio and television, and ordered stations to broadcast "a significant amount of time" for anti-smoking messages.

This effectively meant one PSA for every three tobacco commercials. The PSAs proved so effective that smoking rates began to decline for the first time in history, the tobacco industry withdrew all cigarette advertising, and Congress made such advertising illegal after 1971. Paradoxically, yet in further support of the success of the PSAs, with the passage of that law the bulk of the anti-smoking messages disappeared and cigarette consumption rose again for a while. On balance, however, public health professionals credit the PSAs with having saved many millions of lives by initiating the decline in American smoking.

During the 1960s and 1970s, as media access became an issue, the Advertising Council, and to some extent the very concept of public service announcements, came under criticism as being too narrow in focus. David Paletz points out in Politics in Public Service Advertising on Television that campaigns such as "Only You Can Stop Pollution" were seen as distracting attention from the role of industry in creating demands for excessive energy and in creating dangerous waste products. Other campaigns struck critics as too eager to build consensus around seemingly inconsequential but carefully non-partisan concerns. The networks sought to distance themselves from the Ad Council, and to set their own agenda by dealing directly with the organizations themselves. Local stations were under additional pressure from innumerable new community-based organizations seeking airtime; many stations created and produced announcements in an effort to meet local needs especially since the FCC had come to require that stations report how many PSAs they presented and at what hour.

In the 1980s, a number of stations long closely held by their founders' families, went public or changed hands. The resulting debt load, mounting costs, as well as increased competition from the new media, all resulted in demands for greater profitability. Most unsold airtime was devoted to promoting the station or network. Moreover, deregulation saw government relinquishing the model of trusteeship of a scarce national resource in favor of a marketplace model. To some extent offsetting this trend, were growing concerns about the illicit drug problem. The Advertising Media Partnership for a Drug-free America ("This is your brain..." over a shot of an egg: "This is your brain on drugs. Any questions?" over a shot of an egg frying), was set up by a group of media and advertising agency executives, spearheaded by Capital Cities Broadcasting Company, then completing the take-over of ABC.

Rallying unprecedented support, the organization mounted the largest public service campaign ever. Indeed, at its height, with more than S365 million a year worth of print lineage and airtime, it rivaled the largest advertising campaign. Consistent with contemporary thinking about the nature of social marketing, the campaign was solidly grounded in McGuire's paradigm of behavioral change: awareness of a problem by a number of people will result in a smaller number who undergo a change of attitude toward the problem; an even smaller number from this second group will actually change their behavior. During the first years of the campaign, its research team documented considerable difference in attitudinal and behavioral change among young people. Later results were less hopeful as a number of societal factors changed and media time and space became less readily available.

Other recent developments included two distinctive strategies. The Entertainment Industries Council combined high-profile film, television and recording stars doing network PSAs with depiction efforts: producers, writers and directors incorporated seat belt use, designated drivers, and AIDS warnings and anti-drug references in story lines. The other major development, championed and often carried out by consultants, was the appearance of the Total Station Project. Stations would adopt a public service theme, and, often after months of planning and preparation, coordinate PSAs with station editorials, heavily promoted public affairs programs and features in the local news broadcasts. Total Station Projects most frequently are aired during sweep periods, the months when the station's ratings determine the next year's commercial time prices.

-George Dessart