As digital marketing technologies keep advancing, virtual endorsers have become increasingly common in advertising. However, some brands adopt them without carefully considering whether such endorsers align with their brand identity, showing a blind trend-following tendency. To explore the underlying mechanism and its boundary conditions, this study starts from the identity relationship between brands and consumers. Through a 2 (endorser type: virtual vs. human) × 2 (brand type: local vs. global) between-subjects experiment, it examines how virtual versus human endorsers influence consumers’ purchase intentions across different brand types, as well as the boundary conditions of this effect. The results of the ANOVA and mediation tests reveal that brand type exerts a significant moderating effect on endorsement effectiveness. For local brands, human endorsers are significantly better at stimulating consumers’ purchase intentions than virtual ones; for global brands, no significant difference exists between the two types. Further analysis shows that perceived brand localness plays a moderated mediating role: virtual endorsers weaken the perceived localness of local brands, thereby reducing their promotional effectiveness, whereas this mechanism does not hold for global brands. By introducing brand type as a key boundary condition, this research not only provides empirical support from a brand globalization perspective for the situational adaptability of virtual endorser marketing, deepening the understanding of the alignment between digital endorsers and brand identity, but also addresses enterprises’ confusion over emerging technology application. In practice, the findings suggest that companies should not blindly follow the virtual endorser trend. Instead, they should prioritize the fit between endorsers and brand positioning. Local brands should adopt virtual endorsers cautiously as their effectiveness is weaker than human endorsers, while global brands can choose flexibly without concerns about diminished effectiveness. This study provides both a theoretical foundation and actionable guidance for companies looking to make smarter use of digital technologies and tailor their endorsement strategies to different brand contexts.