Online reputation represents an important driver for platform-mediated transactions. Reputation portability captures the notion of allowing users to transfer their reputation–often in the form of numerical rating scores–from one platform to another. The effectiveness of reputation as a driver of trustworthiness within platforms is well-understood. However, the benefits of porting reputation across platform boundaries are unclear as there is still little empirical evidence. In this article, we employ a multi-method approach to evaluate the interplay of on-site and imported reputation. First, we report results from an online experiment, showing that imported ratings represent a powerful source of online trust. Moreover, we provide a rationale for complementors deciding on whether or not to import reputation. Second, based on empirical data from an actual e-commerce platform, we investigate complementors’ ability to attract demand through importing ratings. Last, we sketch out a field experiment to evaluate external validity and effectiveness of reputation portability in the wild.