暮光绝恋
public service advertising (PSA)，详见维基：Public service advertising is the use of commercial advertising techniques for non-commercial purposes (see also propaganda). Typical topics for public service advertising include public health/public safety issues, emergency preparedness instructions, natural resources conservation information, and other topics of broad interest.Public service advertising campaigns are widespread around the world. Such advertising is generally produced and distributed on a cooperative basis by governmental agencies or nonprofit organizations acting in concert with private advertising and mass media companies. In most cases, the nonprofit provides the programming that is to be advertised, while the participating advertising agency and media companies provide creative services, media planning, and dissemination services on a pro bono basis.http://en.wikipedia.org/wiki/Public_service_advertising
