This chapter explores the strategic marketing framework of Segmentation, Targeting, and Positioning (STP), a core process for delivering customer value and achieving competitive differentiation. The chapter begins by examining the rationale for market segmentation and outlines various segmentation bases, including demographic, geographic, psychographic, and behavioural approaches. It then discusses how to evaluate and select target markets using criteria such as segment size, growth potential, and strategic fit. The positioning section highlights the importance of crafting a distinct and compelling brand image in the minds of target customers, supported by positioning statements, perceptual maps, and consistent marketing mix alignment. The chapter also examines contemporary developments in digital STP, including big data, behavioural targeting, and influencer marketing, while critically addressing ethical concerns such as data privacy, algorithmic bias, and social responsibility. Through practical insights and real-world examples, this chapter equips marketers with essential tools to design and deliver effective customer-centric strategies.