Billboard messages are advertisements that are placed on large outdoor signs, usually along highways and roads. They are typically used to promote products, services, or events. The term 'billboard messages' can also refer to the text or images that are printed on the sign itself. The crossword solution for this term is ADS, which stands for 'ADVERTISING'. ADS are a form of marketing communication used to persuade an audience to take some action, such as buying a product or service.