The document discusses market segmentation and targeting. It defines market segmentation as dividing customers into homogeneous groups based on characteristics. There are four levels of segmentation from broad segments to niches. Effective segmentation requires segments be measurable, substantial, accessible, differentiable, and actionable. The document also outlines steps to target marketing, including identifying and profiling buyer groups, selecting segments, and establishing benefits. Companies must manage segmentation by appointing segment managers and balancing the costs of targeting multiple segments.