The document discusses various factors related to message sources, content, and channels in promotional planning. It provides examples of Tiger Woods' lucrative endorsement deals with Nike starting in 1996. It also shows diagrams of the persuasion matrix that outlines elements to consider, including the source's ability to gain attention, the receiver's ability to comprehend the message, and which media channels will increase message presentation and persuasiveness. Celebrities are often used as sources due to their attractiveness and ability to induce persuasion through identification, though they also carry advertising risks if their behavior affects their credibility.