The value of enterprise social media applications, components, and users is difficult to quantify in formal economic terms such as Return On Investment. In this work we propose a different approach, based on human service to other humans. We describe a family of metrics, Return On Contribution (ROC), to assist in managing social software systems. ROC focuses on human collaboration, namely the creation and consumption of information and knowledge among employees. We show how ROC can be used to track the performance of several types of social media applications, and how ROC can help to understand the usage patterns of items within those applications, and the performance of employees who use those applications. Design implications include the importance of “lurkers” in organizational knowledge exchange, and specific types of measurements that may be of value to employees, managers, and system administrators.