The SMP. Also known as the USP. It stands for Single Minded Proposition, or Unique Selling Point. It's the guiding light of any campaign.
To build an ad campaign without one is like building a new house but neglecting to pour a foundation. It's not a "nice to have," it's a "do or die" kind of thing. And believe me, you're entering a world of hurt if you and your agency tries to create anything without one.
Think of it like having 20 darts, a dartboard, a blindfold and being spun around a few dozen times before your first throw. If you get lucky, one might hit the target. If you get really really lucky, you may hit a bullseye. Chances are you'll hit the window or your creative director before you do. And that's just no good.
Here's a rundown of the SMP, and some tips on how to write one. Plus, examples of some of the greats. Now, you have no more excuses.