What is 3 key messages?

Could you elaborate on what you mean by "3 key messages"? Are you asking about identifying three essential points or themes that are conveyed in a particular piece of content, such as an article, presentation, or speech? Or are you referring to a specific context or industry where "3 key messages" might hold particular significance? Without more context, I can only generally suggest that the three key messages could be the main ideas, takeaways, or calls-to-action that are intended to resonate with the target audience. Can you provide some additional details or clarify your question?