E-Commerce remains a driving force of business for the next years. But online sales channels typically lack the effects of customer loyalty which is an important success factor for retailers, lowering their overall marketing costs. Customer loyalty can be achieved only by knowledge about the customers behaviour and preferences. These have to be respected in the communication with the customer. Mass mailings and un-specific advertisings on the retailers' web sites are lowering loyalty, whereas specific messages of value for the customer are raising his loyalty. Up to date, knowledge about customers is often limited to the direct sales transactions. In our approach, a new way of acquiring knowledge about customers is suggested, which allows a deeper insight on his preferences. This is done by coupling the already present information about customer behaviour with external data describing events which can influence this behaviour. Finding correlations between those different kind of data allow a deeper model of the customer which can be utilized for doing more specific marketing actions.
