Blockchain has the potential to significantly shape the way in which interpersonal and inter-organizational relations will be managed. Despite high expectations, the technology lacks real-world applications that go beyond cryptocurrencies and that convince with efficiency and effectiveness. The gap between visions and theory, on the one hand, and reality, on the other hand, triggered a debate on the future of blockchain and the role of IS research in shaping this future. However, researchers currently struggle to make meaningful quantitative analyses and predictions regarding where and how blockchain is efficiently and effectively applicable. One reason for this is conceptual fuzziness, to which this paper points out. The author identifies three issues, i.e., presence of (i.) terminological ambiguities, (ii.) concept proliferation and conceptual inconsistencies, and (iii.) technological determinism, which IS research needs to clarify if the discipline wants to make reliable predictions about compelling use cases of blockchain.