Abstract

This Systematic Literature Review (SLR) examines how celebrity and influencer endorsements shape consumer purchase intention (CPI) across digital platforms. Reviewing 30 empirical studies published between 2021 and 2025, the analysis synthesizes key theoretical, relational, and behavioral mechanisms that drive endorsement effectiveness within the digital customer journey. Findings consistently show that source credibility, specifically attractiveness, trustworthiness, and expertise, forms the core antecedent of CPI. Among all variables, brand-endorser congruence emerges as the strongest mediator, enabling endorsement cues to translate more effectively into favourable consumer evaluations and purchase-related decisions. Additional mechanisms such as emotional resonance, parasocial interaction, and social media engagement further strengthen endorsement impact in competitive digital markets. Grounded in the Source Credibility Model and Match-Up Hypothesis, this review proposes an integrated framework explaining how digital brand equity is constructed through congruence and credibility-based pathways. The study offers actionable implications for strategic endorser selection and highlights opportunities for future research, including longitudinal examinations and the emerging influence of virtual endorsers.