Roy Grace, a US creative director, has a check list for creative ideas:
1 Is it the kind of idea that’s never ever been done before by anyone else in the product category?
2 Is it an idea you can do many variations on, enabling it to last many years?
3 Is it not only informative but entertaining as well? Does the message move you?
4 Does it make people think? Are people actually involved in the selling premise so they participate in the ad?
5 Do you like it—not because it’s correct, or clever, or powerful— but genuinely like it? Because if you do, the chances are your audience will like the product.
[also cited by John Machado in Creating Desire]
-from Design Manual