Examining the Impact of Social Media Influencer Marketing on Generation Z Purchase Intention with the Moderating Role of Brand Authenticity

Abstract

The objective of this study was to investigate the effect of social media influencer marketing on purchase intention among Generation Z consumers while examining the moderating role of brand authenticity in strengthening this relationship. This study adopted an applied quantitative approach using a descriptive–correlational design based on structural equation modeling. The statistical population consisted of Generation Z social media users residing in Tehran, Iran. A total of 412 participants were selected using a multi-stage cluster sampling method combined with purposive screening to ensure active engagement with social media influencers. Data were collected through a structured questionnaire measuring influencer marketing perceptions, brand authenticity, and purchase intention using validated Likert-scale instruments. Content validity was confirmed through expert evaluation, and reliability was assessed using Cronbach’s alpha and composite reliability indices. Data analysis was conducted using SPSS and SmartPLS software through a two-step procedure involving measurement model validation and structural model testing. Moderation analysis was applied to examine the interaction effect of brand authenticity on the relationship between influencer marketing and purchase intention. The results indicated that influencer marketing had a significant positive effect on Generation Z purchase intention. Influencer marketing also significantly enhanced perceptions of brand authenticity, while brand authenticity itself demonstrated a significant positive impact on purchase intention. Structural model analysis confirmed that brand authenticity played a significant moderating role, strengthening the relationship between influencer marketing and purchase intention. The proposed model showed substantial explanatory power, indicating that authenticity perceptions amplify the persuasive effectiveness of influencer marketing strategies. The findings suggest that influencer marketing is an effective digital marketing strategy for influencing Generation Z consumers, particularly when supported by strong perceptions of brand authenticity. Authenticity functions as a critical boundary condition that enhances consumer trust, reduces skepticism toward promotional content, and strengthens behavioral intentions. The study highlights the importance of aligning influencer identity with authentic brand values to maximize marketing effectiveness in contemporary social media environments.