Final answer:
A marketer concerned with convincing consumers that a brand is distinctive and in demand is using the product differentiation positioning strategy.
Step-by-step explanation:
A marketer who tries to convince consumers that a particular brand is distinctive and they should demand it is concerned with product differentiation positioning strategy. Product differentiation refers to any action that firms take to make consumers think their products are different from their competitors. This can include physical aspects of the product, location from which it is sold, intangible aspects, and perceptions of the product.