Final answer:
The concern with using humor appeal in advertising is the subjectivity of humor and the potential for it to offend or be misunderstood by different audiences.
Step-by-step explanation:
A concern when using humor appeal is that what adults find humorous, children may not, and vice versa. Additionally, people have different senses of humor, and what is amusing to one may be offensive to another. In advertising, there is a risk that humor can lead to misunderstanding or “wearout” where the audience gets bored quickly. This is especially important in formal communications, where humor and sarcasm are better avoided to prevent misunderstandings. Understanding your audience's preferences and cultural context is key, as humor can be deeply personal and varies greatly across different societies.