Sound contracts are an obvious necessity for an IT outsourcing relationship, but they are by far not the only prerequisite for achieving a truly successful relationship. Companies that establish successful outsourcing implement active relationship management in order to reach a good relationship quality. However, relationship quality as a central concept in IT outsourcing governance has not been thoroughly analyzed and applied yet, neither in scientific literature nor in practice. Stefan Blumenberg addresses these shortcomings and shows how relationship quality can be measured as a seven-dimensional construct and which are the crucial factors that are required to achieve high-quality relationships. Based on a case study series with 18 banks and their respective IT service providers in Germany, Blumenberg demonstrates that knowledge transfer mechanisms strongly influence relationship quality. Banks with clearly defined contact structures (e.g. retained organizations) and knowledge transfer mechanisms for exchanging implicit and explicit knowledge (e.g. trainings, job rotation) exhibit a good relationship quality and, as a result, achieve a successful outsourcing relationship.