Selling financial services requires deep knowledge about the product domain as well as about potential wishes and needs of customers. In this context, sales representatives can differ significantly in their expertise and level of sales knowledge. Therefore, financial service providers ask for tools supporting sales representatives in the dialog with the customer. In this chapter we present the knowledge-based recommender environment Koba4MS (Knowledge-based Advisors for Marketing and Sales) which allows a flexible mapping of product, marketing, and sales knowledge to the representation of a recommender knowledge base. In Koba4MS, we integrate diagnosis, personalization, and knowledge acquisition techniques, thus providing an infrastructure for the interactive selling of financial services.