Virtual influencers in digital marketing: a PRISMA-based systematic literature review and thematic synthesis of engagement, trust, and ethical challenges

Abstract Virtual influencers (VIs) are AI-generated personas that are reshaping digital marketing, particularly through social media. While marketing research on human influencers is extensive, systematic insights into VIs remain limited. This study conducts a systematic literature review (SLR) of 73 peer-reviewed articles from 2016 to 2024 using the PRISMA framework and multiple analytical tools (RStudio, VOSviewer). Key research questions address the evolution of VIs, their comparative effectiveness with human influencers, and how perceived trust and authenticity impact engagement. Through thematic, content, and comparative analyses, the study uncovers key trends, identifies research gaps, and proposes a conceptual framework to guide future research in marketing and communication.