There are many ways a company or advertiser is able to control who their target audience is. First they want something effective, like the Tootsie pop commercial, that ranges to everyone, the bright colors and characters were something to pull in the attention of a younger audience, children. But at the same time humor is used to catch everyone.
Depending on your audience, this can range from colors, sounds, characters, and so on. A main way for advertising a younger audience is of course color, and is usually TV advertised. Something for older audience like adults, and elders would be TV, radio, and even the papers, or even flyers in this case.
Other ways to advertise would be public speeches/demonstrations, events, online ads, social media, and so on