This thesis examines how Customer Experience Management drives competitive advantage in direct-to-consumer (D2C) e-commerce, using Emma – The Sleep Company as a case study. In the online mattress market, where customers cannot physically test products, it is essential to build trust and provide high-quality service and post-purchase support. The research examines Emma’s customer-centric structure and the operational processes that enable a smooth customer journey across online channels. A key focus is the role of Net Promoter Score (NPS) as a metric for assessing customer loyalty and guiding experience improvements. The thesis reviews the theoretical foundations of NPS, evaluates its application at Emma and analyses the evolution of the survey design to improve data quality and business relevance.