Long before social media existed, the proto-tweets of advertising had penetrated American popular culture: 'A mind is a terrible thing to waste.' 'Where's the beef?' 'A diamond is forever.' 'Think different.' You'd be hard pressed to find a writer's craft that has more directly influenced the vernacular.
The qualities I look for in planners or creatives is very much the same thing. Beyond the givens of talent and work ethic, I really look for people who are inspired by the everyday, people who are not afraid of the obvious and are able to reinterpret it into a creative and interesting manner.