Celebrities are one thing that is used in all forms of advertising. Here are some ways:
Television: You might be watching TV and you see a hot dog commercial. in that commercial, you might see a hot dog commercial with Michael Jordan in it. He's saying,
"It's not summer 'till you have a Ballgame hot dog..."
They just used a celebrity. People will then say,
"Ooh! Michael Jordan eats Ballgame hot dogs! Well, if Michael Jordan eats them, I will too!"
You also get celebrities on the radio the same way.
"Hi! I'm Kon Poric, inventor of the Poric vacuum cleaners. It picks up twice the dirt of your current vacuum cleaners. Buy a Poric today!"
Poric is a popular person! When people hear him talk, people listen to what he has to say, which is an advertisement.
You also see advertisements on the internet itself. For example,
when you go onto a sports web page, there might be an ad that says "Hi,
I'm Don Belway. I drink Dollsport."