As consumers increasingly look to connect with companies online, lackluster Web experiences will damage many brands. But better functional design won't solve the problem. Instead, Forrester recommends that companies master the three principles of a new approach that we call Emotional Experience Design (EED): Address customers' real goals, develop a coherent personality, and engage a mix of senses. Firms can get started by focusing their research on uncovering users' emotional needs, capturing emotional feedback in testing, and charting a course to Experience-Based Differentiation (EBD).