My wife has me trying to eat gluten-free for a few weeks.
That means no bread, cookies, pizza, pasta. It’s like I’ve been told, “Ian, from now on, food will suck”.
But I’m doing it. Voluntarily.
If Dawn had simply told me, “Eat less starch, eat more veggies, and reduce caloric intake,” I’d totally fail.
What’s the difference? I need an opponent: Gluten is the bad guy. Tell me to eat smarter and I’m the bad guy. I’m not a bad guy! The result of me having gluten as a focus: I’m eating less starch, eating more veggies and taking in fewer calories. Sound familiar?

Apply it to marketing

The greatest marketing campaigns in history created a focal point: An opponent, harmless or not, that we can focus on as we adjust our behavior.
Why’d we go to the moon? The USSR launched Sputnik. If you don’t think JFK’s speech launched one of the most ambitious marketing campaigns in history, well, better think again.
Why did 1 in 11 American adults do the Atkins Diet? Because we all decided we need to lose weight? Noooo. Because it turns out that the enemy is carbohydrates. It was easy to focus on a single opponent. It’d make a lot more sense to just reduce fat intake and exercise more. But there’s no focus. It’s a lot easier to sell a concept if there’s a single bad guy.
This isn’t a cynical statement on my part. I’m not saying we have to create enemies to do great marketing. Great marketing, though:

1. Looks at the change in behavior we want to create;
2. Finds an element that can inspire people to make that change;
3. Focuses messaging on that element.

So yeah—every marketing campaign needs a gluten.