on a store by store basis is logistically difficult and is now not considered a necessary part of category management; it is a concept now referred to as micromarketing. Nevertheless, most grocery retailers will segment stores at least by size, and select product assortments accordingly. Wal*Mart's Store of the Community, implemented in North America, is one of the few examples of where product offerings are tailored right down to the specific store. Rationale for category management One key reason for the introduction of category management was the retailers' desire for suppliers to add value to their (i.e. the retailer's) business rather than just the supplier's own. For example, in a category containing brands A and B, the situation could arise such that every time brand A promoted its products, the sales of brand B would go down by the amount that brand A would increase, resulting in no net gain for the retailer. The introduction of category management imposed the condition that all actions undertaken—such as new promotions, new products, re-vamped planogram / schematics, shopper and consumer insights, and the introduction of point of sale advertising etc.—be beneficial to the retailer and the shopper in the store. A second reason was the realization that only a finite amount of profit could be milked from price negotiations and that there was more profit to be made in increasing the total level of sales. A third reason was that the collaboration with the supplier meant that supplier's expertise about the market could be drawn upon, and also that a considerable amount of workload in developing the category could be delegated to the supplier. Definition of a category The Nielsen definition of a 'category', used as the basic definition across the industry, is that the products should meet a similar consumer need, or that the products should be inter-related or substitutable. The Nielsen definition also includes a provision that products placed together in the same category should be logistically manageable in store (for example there may be issues in having room-temperature and chilled products together in the same category even though the initial two conditions are met). However, this definition does not explain how the process often works in practical retailing situations, where demographic or marketing considerations take precedence. The next step of Category Management is to understand the mechanism of the customer's decision concerning purchases of a given category. The decision-making process