Super-Duper Bowl Ads

Before I share the Super Bowl TV commercials I enjoyed most, I have a probing question which has always puzzled me.

In the context of the adjective "super-duper," what exactly is a duper?

Oh, sure, there is wondrous duper involved, heightened duper even. I would simply like to know what duper is. Everyday, common duper.

That would be super.