Purpose - The purpose of this chapter is to examine the connection between actual variety (the number of stock-keeping units (SKUs)) and amount of useable variety that the consumer perceives. The optimal combination for a retailer is to offer an assortment that maximizes the perceived assortment variety while minimizing the perceived inter-item complexity. Both measures are a function of the actual variety offered in an assortment but other factors such as attribute structure of the individual items, assortment organization, and individual differences can alter the way the actual variety is perceived. Design/methodology/approach - The main methodology used in the chapter is a comprehensive, critical literature review of the empirical research on the topic. Findings - We find that while assortments with a large number of SKUs are desirable for attracting consumers to the category, too large assortments can result in consumer frustration and confusion. On the other hand, when assortments are small, the perceived variety or attention to the category may be limited. Value/originality - Our review shows ways a retailer can adapt to these challenges. First, we show that assortments are viewed in stages. In the first stage, high perceptions of variety are beneficial. When assortments are small, increasing perceived variety can be accomplished by increasing the number of subcategories within the assortment, adding in packaging cues, or using other emotional affective descriptors to further define options within the assortment. In the second or choice stage, too much variety can increase perceived complexity. Perceived complexity at this stage can be reduced by simplifying the complexity of the individual items within the assortment by increasing alignability of attributes, using a simplifying external organizational structure for the assortment, or helping consumers learn their preference.