Companies in emerging economies increasingly adopt electronic-signature (e-signature) systems, yet evidence on their performance payoffs and complementarities with other digital investments remains limited. This study examines whether e-signature adoption improves sales and whether that effect depends on digital-channel breadth, innovation spending, and e-commerce participation. Using cross-sectional data on 3,747 Ecuadorian companies from the 2022 national survey, we estimate pooled OLS models with heteroskedasticity-robust errors and extensive industry, size, and regional controls. Results show that e-signature adoption is associated with statistically significant but economically modest gains in sales, providing partial support for the direct-effect hypothesis. No complementarity is detected with multichannel digitalization, indicating additive rather than synergistic effects. Innovation expenditure exhibits the largest and most robust association with sales, whereas the e-signature × innovation interaction is not robust once covariates are included. In split sample tests, the e-signature coefficient remains positive and significant among e-commerce companies but not among traditional companies, underscoring a contingent fit between procedural digitalization and remote-sales contexts. Across specifications, company fundamentals explain most revenue dispersion, highlighting the primacy of structural heterogeneity over isolated technologies. These findings refine resource-based and dynamic-capabilities perspectives by showing that e-signature acts as a process hygiene tool whose value materializes chiefly when embedded within broader innovation and e-commerce capability bundles.