With the rapid advancement of mobile internet technologies, the channels through which firms interact with consumers have proliferated, fundamentally transforming consumption patterns. Focusing on the emerging trend of omnichannel development in the mobile internet era, this book draws on multiple sources of data—including laboratory experiments, field experiments, and survey data—to present research findings from the perspectives of firms, channel intermediaries, and consumers. Specifically, it examines firms’ channel management strategies, the positioning and functions of channel intermediaries, and consumers’ cross-channel migration behaviors. Grounded in real-world challenges in omnichannel practice, the book aims to generate insights into consumer behavior in omnichannel contexts and to uncover the underlying mechanisms through which firms can effectively operate omnichannel systems.