What term describes a retailer that offers a deep assortment of branded merchandise in a single category?

The term that describes a retailer offering a deep assortment of branded merchandise in a single category is referred to as a "Category Killer." This type of retailer typically dominates a particular category by having a vast selection of products and competitive pricing, which makes it difficult for smaller competitors to compete. For example, stores like Toys "R" Us in the toy category or Best Buy in the electronics category are considered category killers because they provide extensive variety and depth of branded items, thus attracting a significant share of the market for that specific product category.

In contrast, a discount store generally offers a wide range of products at low prices but may not specialize in one particular category. A department store provides a variety of goods across multiple categories, while a specialty store focuses on a narrow range of products but may not have as extensive a selection within that category compared to a category killer. Thus, the defining characteristic of a category killer is its ability to overwhelm the market for a specific type of merchandise with a comprehensive assortment.