Trust as the Conversion Mechanism: How Social Media Marketing Activities and Influencer Credibility Shape Young Consumers’ Buying Behaviour in Pakistan

Abstract

Purpose – This study examines how brand-led social media marketing activities (SMMA) and influencer credibility (IC) shape the buying behaviour of young consumers in Pakistan, and whether consumer trust carries these effects. Drawing on the Stimulus–Organism–Response model, trust theory and the persuasion knowledge model, it tests direct and trust-mediated routes from both stimuli to buying behaviour. Design/methodology/approach – Survey data were collected online from young social media users in Pakistan (N = 180 usable responses after screening for duplicates and careless responding). The model was estimated with partial least squares structural equation modelling (PLS-SEM) and 5,000 bootstrap resamples, complemented by PLSpredict, an importance–performance map analysis (IPMA) and a permutation-based multigroup analysis by gender. Findings – SMMA (β = .481) and IC (β = .479) both strongly increase consumer trust (R² = .751), and trust (β = .443) and IC (β = .371) increase buying behaviour (R² = .672). SMMA has no direct effect on buying behaviour (β = .066, p = .485): trust fully mediates its influence, whereas it only partially mediates the influence of IC. The IPMA identifies IC as the most important but lowest-performing driver of buying behaviour. The direct influencer route is significant for male respondents but not for female respondents (Δβ = -.469, p = .010), for whom the effect runs entirely through trust. The model shows high out-of-sample predictive power for buying behaviour. Practical implications – Marketers should evaluate brand content by the trust it builds rather than by reach alone, prioritise credible and authentic influencer partnerships, and design trust-building influencer content for female audiences. Originality/value – The study integrates brand-led and influencer-led stimuli in one S-O-R model in an under-researched South Asian market, shows that trust plays different mediating roles for the two stimuli, and reveals a gendered direct influencer route.