: Product customization has become a commonplace topic in the last few years. Cars can be equipped with numerous gadgets, cell phones come in different colours and so on. In all these cases, product customization is a means of marketing. In the fixed line telecommunications market customization is a necessity. This difference is due to the fact that technical infrastructure differs from customer to customer. While one customer can easily be connected to fibre, another one might only be connected via miles of copper cable. Hence, every single customer's product has to be customized. This kind of technical customization is not only increasing complexity in product realization, it also means that product offers have to be custom tailored. Otherwise customers might be offered products that cannot be realized at their homes. For sales talks, this information is crucial. If sales agents do not know which product a customer can buy, they either sell the wrong product or keep the customer...