Abstract: The article conceptualizes global performance indicators as public measures that are powerful but also receive a wide range of criticism. Global performance indicators derive their power from combining three analytically distinct elements: (a) commensuration (comparing performances on a common metric), (b) visual simplification (presenting performances in an appealing format), and (c) serialization (framing performance as a continuous developing property). However, the very same elements are often subject to criticism. The producers of global performance indicators, therefore, defend methodologies and the validity of commensurated numbers, meet charges of visual oversimplification by professing sobriety and nuance, and balance temporal continuity and discontinuity. By conceptualizing global performance indicators as powerful and criticized public measures, the article draws attention to the Janus face of valuation, which the producers must tackle continuously. Investing considerable time, energy, and resources, these organizations are a key feature of today’s vast indicator culture.