This '70s commercial is for Mr. Pibb, a soft drink by The Coca-Cola Company. 

Hockey players Marty and Gordie Howe are sparring on the hockey rink. Gordie says he thought Marty made a mistake when Marty decided to be a defensive hockey player instead of an offensive hockey player like he, Gordie, was. Gordie thought differently when Marty made the All-Star team, and was corrected. 

Gordie now thinks that Marty’s decision to make Mr. Pibb his favorite soft drink is questionable. 

Gordie: “He said it’s not a root beer or a cola, but a unique blend of flavors!”

Marty: “And I say that Mr. Pibb is gonna be big some day, you know?”

Gordie responds: “Maybe we’re onto something." Marty disputes the “we." 

The end shot is of a Mr. Pibb bottle and banner: “We’re onto something: taste why!”