We co-create values for brands on social media: The roles of social endorsements

Drawing on herding theory and service-dominant logic, this study examines how the sheer volume of "likes" surrounding a brand post shapes downstream value-creation outcomes on social media. Using a between-subjects online experiment with 317 social media users recruited through Amazon Mechanical Turk, the SmartPLS results show that stronger crowd endorsement significantly enhances brand credibility, brand symbolism, and social brand value, which in turn increases consumers' willingness to co-create value with the brand. The findings reveal two distinct psychological pathways: brand credibility acts as a cognitive-evaluative mechanism that directly drives individual-level value co-creation, whereas brand symbolism and social brand value operate as identity-based and relational mechanisms that mobilize collective engagement through social support. The findings reconcile social-proof and social-capital perspectives by showing that crowd cues strengthen a brand's symbolic and relational capital, which then energizes cooperative behaviors central to service-dominant logic. The study extends prior research from asking whether crowd endorsement works to explaining how it works in shaping value co-creation in digital environments. Managerially, the results suggest that brands should move beyond merely accumulating visible endorsements and instead cultivate symbolic meaning and social value to foster supportive communities and stronger co-creation. Future research may further validate these mechanisms across cultural, and platform contexts and examine boundary conditions such as privacy concerns and algorithmic reach.