The biggest mistake in billboard advertising is trying to say too much. A billboard is not designed for long explanations. It is designed for quick memory.
Most billboard messages should be short, direct, and easy to process. OAAA creative best practices recommend short messages and warn that too many elements compete against each other. The common industry rule is around seven words or fewer for the main message.
A plumber does not need to list every service on the board. “Fast Plumbing Help” may work better than “Residential and Commercial Plumbing, Drain Cleaning, Water Heaters, Leak Detection, Emergency Repairs, and Fixture Replacement.” The second message may be accurate, but nobody can read it at 55 miles per hour.
The best billboard message usually answers one question: why should the customer remember you?
Examples:
Each of those messages is short, memorable, and tied to a customer need. That is what makes billboard copy work.
The call to action should also be simple. A phone number, website, or easy brand name is enough. Do not overload the board with QR codes, multiple phone numbers, long URLs, social media handles, and a paragraph of text. The more things you add, the less people remember.
Best rule: one message, one idea, one call to action.