This chapter presents an empirical investigation of why customers switch channels in an omnichannel environment, building on the qualitative foundations established in Chapter 3 . Using survey data from electronic goods shoppers in Vietnam, this study applies the Theory of Planned Behaviour (TPB) to examine how attitudes, subjective norms, and perceived behavioural control shape both channel switching intention and actual switching behaviour. The findings reveal that while attitudes to switching and perceived control influence switching behaviour through intention, subjective norms directly drive switching behaviour. The results stress the powerful role of social influence, an area often overlooked in omnichannel research for channel switching behaviour. The study also expands understanding of attribution-based decision-making, showing that customers evaluate channel attractiveness and switch strategically to maximize value, reduce uncertainty, and enhance decision quality. From a practical perspective, the chapter offers retailers actionable recommendations to design more seamless and supportive omnichannel journeys. By understanding key drivers such as trust, perceived benefits, and cross-channel synergy, firms can tailor communication, enhance experience consistency, and leverage social influence to guide customers confidently across channels. The chapter offers an evidence-based and robust framework that helps decode channel switching behaviour in today’s fast-moving retail landscape.