Radio advertisements typically last around 30 seconds to immediately introduce the product. They use music and sound effects to set the tone and keep listeners engaged. Music helps portray the desired emotion - for happy products it's usually upbeat, while sad topics use more subdued sounds. Sound bites are also included to indicate what the ad is about. When creating their own radio ad, the author learned it should be 30 seconds to follow conventions, use clear voiceovers with an English accent, and consider adding memorable music rather than having it seem like a speech.