Examining Effects of Social Media Influencer Marketing on Coca-Cola Purchasing Behaviour in Galle, Sri Lanka.

Abstract

Social media influencers are now important opinion leaders that affect consumer trust and purchasing decisions as digital marketing develops, but there is still limited data on their efficacy in Sri Lanka's fast-moving consumer goods (FMCG) beverage industry. This study examines how consumer social media engagement and exposure to influencer-generated content affect Coca-Cola purchasing behavior among social media users in Sri Lanka's Galle District. Convenience sampling was used to select 384 respondents for a quantitative cross-sectional survey guided by source credibility and social proof perspectives within a positivist, deductive framework. Data were analyzed in SPSS using reliability testing (Cronbach's alpha), Pearson correlation, and multiple regression. All constructs showed satisfactory to good reliability (α = 0.601–0.788). Correlation analysis indicated significant positive relationships among consumer social media engagement, exposure to influencer-generated content, and purchasing behavior (p < 0.01). Regression results show that the two predictors together explain 48.7% of the variance in Coca-Cola purchasing behavior (R² = 0.487, p < 0.001), with exposure to influencer content a stronger predictor (β = 0.344) than social media engagement (β = 0.148). Generalizability and causal inference are limited by the cross-sectional design, single-district convenience sample, and focus on one brand. Future research should use experimental or longitudinal designs, expand to multiple districts and beverage brands, and incorporate constructs such as perceived authenticity, attitude toward the advertisement, and influencer credibility to better understand psychological mechanisms underlying influencer effects in Sri Lankan FMCG markets.