It would be good if he illustrated his point with an example of an ad optimized for the 84%. Brand awareness? Advertising online to bring people in-store rather than simply driving clicks? What are good examples?
Brand awareness. An ad for a BMW for example. You're not likely to click and buy the car right there, so it works the same way as their TV ad does -- it'll keep the brand in your memory until you need to make a car purchase decision.