A good public service announcement (PSA) is effective because it is:
Clear and concise: It uses simple language and gets to the point quickly.
Compelling: It grabs the audience's attention and makes them care about the issue.
Informative: It provides accurate and relevant information.
Action-oriented: It tells the audience what they can do to help.
Memorable: It sticks in the audience's mind long after they've seen or heard it.
Additionally, a good PSA is often:
Emotionally resonant: It connects with the audience on an emotional level.
Visually or aurally appealing: It uses strong visuals or sound to enhance the message.
Well-produced: It is professionally made and of high quality.