Similar to traditional brick-and-mortar shops, e-commerce websites also should perform well in terms of various performance criteria in order to win and retain customers. A number of e-commerce performance criteria have been identified in the literature. From the point of view of the manager of an e-commerce website, the relative importance levels customers attribute to these performance criteria are important. In this paper, we propose a new mathematical programming model for estimating the importance levels. The model is based on the Analytic Hierarchy Process and operationalised using goal programming. Application of the model highlights that the criterion ‘‘satisfaction with claims’’ is valued by customers as the most important criterion. This criterion requires coordination with multiple echelons of the supply chain – a clear description by the manufacturer of the product, introducing the correct description in the e-commerce website, processing customer orders accurately, and, picking and dispatching the right product from the warehouse