• Your message is complex. It’s better to have a 60-second message that clearly communicates what you are trying to say than a 30-second advertisement that leaves the listener with questions or confusion.
• There are specific details that need to be included. It’s important to use specifics if you are answering a question that is lurking in the mind of your listener, but don't bore listeners by answering questions no one was asking.

30-second ads are best when:

• Your product or service category is clearly understood and you're making an easy-to-understand offer. Make one point per ad, but make it a very strong point. Do not write a weak message/offer and then try to compensate for it with powerful delivery (dramatic music, sound effects, etc.)

15-second ads are best when:

• You have an incredibly powerful, simple message.
• You are the only advertiser in your business category (car wash, c-store, etc.). If you are the only one advertising and have the name recognition, it’s likely customers will think of your name when they need the products/services you offer.