Market segmentation involves dividing a market into distinct groups based on characteristics like geography, demographics, psychographics, and behaviors. The key benefits are identifying new product opportunities, designing effective marketing programs for homogeneous groups, and improving resource allocation. Segments must be identifiable, accessible, respond uniquely to offerings, be large enough to target, and relatively stable over time. Common bases for segmentation include geographic variables, demographics like age and income, psychographic lifestyle assessments, and behavioral factors.