In this contribution, we study companies engaging in B2C-E-Commerce and their ability to manage the relationship with their customers. We refer to this as companies’ ECCRM-capability and examine its determinants and the impact that all of these factors have on corporate success in E-Business. We construct a covariance structure- (or LISREL-) model for testing our research hypotheses on a subset of 224 cases from a representative survey of 1,308 general companies. We find that companies’ ECCRM-capability largely relies on data collection and –aggregation as well as managerial competence in planning and implementing these measures. We obtain no evidence that companies’ ECCRM-capability increases their success. While collecting customer data proves to be a strong driver for success, aggregating and condensing this data appears to degrade corporate performance.