Omni-channel retailing (OCR) strategies have recently emerged as a powerful engine of growth in the retail industry. The goal is to provide consumers with a seamless and consistent shopping experience across different channels and devices. Success in implementing OCR strategies depends on sophisticated compromises between fulfilment responsiveness and product variety across different product types, consumer segments, and shopping occasions. Failures in OCR strategies to optimize the trade-offs between responsiveness and variety are rooted in a poor understanding of how OCR strategies should...