In this paper, we investigate the relationship between Internet retailer margins and retailer promises regarding product distribution service. We focus particularly on Internet retailing in a drop-ship context, because this model provides a purer separation of these activities and the related costs and constitutes a critical context for the empirical examination of the relationship between retailer margins and promises. Drawing upon retailer and consumer perspectives, we articulate and justify a set of propositions regarding the relationships among different Internet retailer margins and promised product distribution service performance. We examine a sample comprising over 2000 retail transactions with customers and find partial empirical support for the set of propositions. Specifically, the results show that product margins and the margins on shipping and handling are inversely proportional. We also find a direct relationship between promised product distribution service performance and shipping and handling margins even after key product characteristics known to influence the cost side of the margin equation are controlled for. These results confirm an intuitively logical view of the relationships among pricing and promised product distribution service performance. The study also offers insights for practitioners regarding the opportunity to enhance performance in this domain and demonstrates the benefit and power of employing objective measures drawn from the vast array of information captured via online transactions.