For decades, marketers have considered the wisdom of Al Ries and Jack Trout to be the gospel of positioning.  In their two books, “Positioning: The Battle for Your Mind,” and “Marketing Warfare,” Trout and Ries explained their concept that:
Consumers only have space in their brains for a handful of brands in any one category – say fast food, soft drinks, airlines, or athletic shoes.
The consensus number-one brand is the “defender.” Their job is to stay on top and never even acknowledge that the lesser brands exist. Example: Coca-Cola
The consensus number-two brand is on the “offense.” Their job is to try to knock off number-one with comparisons that make their brand look good. Example: Pepsi and the Pepsi Challenge
The next-level brand or brands are called “flankers.” They are not strong enough to take on those top two brands, so they carve out their own position in the marketplace. Example: Seven-up – The Un-Cola. 
But in today’s world of digital disruption, some small, start-up br...