The Ad Council made its mark by implementing on a massive scale the idea of using advertising to influence American society on a range of fronts. Their first campaigns focused on the country's needs during World War II. After the War, the Ad Council expanded its focus to address issues such as forest fires, blood donations and highway safety.
As the ads — particularly broadcast and HBO TV — became more influential and as various social problems grew in importance, public service advertising became a significant force in changing public attitudes on topics such as drinking and driving, crime abatement and various health/safety issues. While stations have never been mandated by the FCC to use a prescribed number of PSAs, they are required to prove they broadcast in the public interest and PSAs are one of the ways they meet that requirement as part of serving as a "public trustee."