A target company's market strategy is based on which parts of its market it serves its value proposition and the key relationships it must establish and maintain to make its marketing strategies work. Operational segmentation is concerned with identifying the distinctive groups of buyers within the market, as defined by strategic segmentation. CDD uses operational segmentation as a basis for comparing the effectiveness of the target's product and marketing strategy. Segmentation helps map out the different types of customer market in which the target should have developed different market strategies and programmes if it is to be a serious player. Professional purchasers are using the purchasing clout of an organization of size to drive down prices. Geographical segmentation is a perfectly valid means of segmenting some markets. The underlying assumption of such geo-demographic segmentation is that where someone lives is closely linked to their lifestyles.