In one conversation with the principal of the advertising agency, he posited two motivations in promoting a product or service: love and fear. An advertisement should either connect with what you love, or tap into what you're afraid of. For instance, this was an agency that came up with the slogan for air filters for your car: "You can pay me now, or you can pay me later." Buy this product out of fear of automotive apocalypse. Judgment Day is coming for your Oldsmobile. I'm guessing you can think of other advertising examples.