This billboard poster, announcing the Lions' arrival at the San Diego Zoo, gave me a laugh. Excellent visual. Notice the balance between the image and copy. When you have a captivating visual like this one, your copy can afford to be more direct and to the point, and vice versa when you have a striking headline. In a lot of ways advertising follows the straight man-funny man dynamic. Two funny men are a little overwhelming, and not very funny. That's the first rule in advertising - balance. The second rule is: there are no rules.