Think about the pantheon of famous advertising tag lines:

Where's the beef.
Milk -- it does a body good.
Coke Is It.

Right up there near or at the top is an exhortation from an athletic wear company: Just Do It.

This month marks the 25th anniversary of that iconic Nike slogan. The ad campaign is where Charles Barkley told us he wasn't a role model: 

And the only time you'll see Kenyan distance runners, Kobe Bryant, Rafael Nadal, Wayne Rooney and few black belts in a room together working out:

The first "Just Do It" TV ad featured a lesser-known athlete, Walt Stack:

In it, the 80-year-old runner jogs shirtless across the Golden Gate bridge, his voiceover explaining that he runs 17 miles per day.

Ken Wheaton, managing editor of Advertising Age, joins the show to talk about the effect of the Just Do It ad campaign.