Wolfgang Lennartz systematically discusses the performance, application possibilities, and limitations of the most important customer evaluation methods according to a criteria catalog, with a particular focus on practical requirements. The author derives these requirements from a comparative analysis of empirical studies on customer evaluation to facilitate the selection of an appropriate method for customer evaluators. It becomes evident that the methods particularly favored by companies, while relatively easy to implement, do not provide a forward-looking monetary customer value. This has only been achievable with approaches that are difficult to implement. Therefore, the author develops a pragmatic model for estimating a prospective monetary customer value based on commonly used retrospective data.