By Dave Kwasnick

So in pondering what makes an ad great, one word popped into my mind.

“Poltergeist.”

Yeah, I didn’t see that coming. Allow me to explain. But first, do you remember the movie? (The original please, not the remake.)

“Carol Ann.”

“Don’t go into the light.”

“You only moved the headstones.”

Then you probably remember this scene: The boy’s creepy clown inexplicably goes missing in his room. (Note to parents: don’t buy your kids creepy clowns.) With ghosts running amuck, he’s pretty freaked out. So the boy looks for it under…the…bed. Slowly, agonizingly he musters the courage to peek into the darkness and sees….nothing. The tension evaporates. Poof! The boy spins back under the covers and BOOM! gets a big ol’ bear hug from Slappy the Satanic Circus Performer.

First time I saw that, I nearly peed myself.

Thirty years later, I watched it with my daughter. Pretty sure she did too.

Point is, we both knew exactly what was coming and we watched anyway. Heck, we secretly yearned for it. Why?

Two words: human nature. We love the delicate interplay between expected and surprise. The expected gives us a context we understand. It draws us in with familiarity, makes us say, “been there before.”  Take the scene from “Poltergeist.” Who hasn’t been slightly traumatized by the sight of a clown during childhood? ‘Nuff said. The surprise? That’s the thrill, the entertainment, the liberation from the ordinary world we all seek – if only for a moment. So when the clown finally popped out, it wasn’t an unwelcomed shock but rather the fulfillment of sought after expectation.

When you get the balance of expected and surprise just right, it’s magic and it never gets old.

Not surprisingly, “Poltergeist” was a huge success at the box office.

Fast forward to this Sunday. We’re gonna see a lot of commercials. The vast majority of them are one-offs created just for this game (though they’ll undoubtedly run throughout the year.) These spots are the product of five, 10, 15 creative teams, armies of social media, account and media people working toward this moment since before the confetti settled at last year’s game.

Yet nestled into this mélange of :30 second eye candy will be a spot that isn’t the singular product of a frantic 12-month birthing process. Nor is it really new. In fact, it’s the extension of a campaign that’s been running for seven years. And, like the clown in “Poltergeist”, we see it coming every time.

Yet we can’t stop watching.

It’s the Snickers campaign. I don’t laud it because I’m especially fond of Snickers (I’m not.) Or because I have a deep respect for the work BBDO does (I do.) I single it out because it shares something truly great, supremely effective advertising campaigns all have in common. You guessed it – the blend of expected and surprise.

Snickers expected, captured in wonderfully simple language, is “You’re not you when you’re hungry.” It’s an insight we can all relate to. Who hasn’t bitten someone’s head off when blood sugar dips way below the refill line?

Been there before.

And the surprise? Substituting an iconoclastic list of entertainment legends to personify people’s surly, calorie-deprived alter egos. Betty White. Aretha Franklin. The late Abe Vigoda. And this year Wilem Dafoe.

Yes, essentially it’s the same spot every time. But in this case, it does more than give us a moment of mirth or a fleeting bit of entertainment. It makes us, consciously or otherwise, grab a Snickers when hunger pangs have us acting, well, not like us. Think about it. Bet you’ve had a Snickers recently. How do I know? Because this campaign has taken Snickers from the back shelf of the candy aisle to a brand poised to crack the $1 billion mark.

When you get the balance of expected and surprise just right, it’s magic and it never gets old.

And that’s not just human nature.

It’s damn good business, too.

Dave Kwasnick is Partner, Executive Vice President, Chief Creative Officer at Gatesman+Dave, a fully integrated, independent marketing communications agency with expertise in branding, advertising, digital, public relations, social media, and media planning and buying. To learn more, please visit www.gatesmandave.com or join in on the conversation athttp://www.facebook.com/GatesmanDave or http://www.twitter.com/GatesmanDave.