Purpose This study aims to develop and test a process model of the effect of social media use by business-to-business (B2B) salespeople on their value cocreation and cross/upselling performance. Adopting a research acquisition perspective, the authors claim that salesperson’s social media use is critical for generating social capital – an operant resource characterized by superior market knowledge, reputation and networking – which, in turn, directly and synergistically enhances value cocreation and cross/upselling outcomes. Design/methodology/approach A model is developed based on extant sales research on salesperson’s social media use and social capital theory. Data from B2B salespeople is analyzed using structural equation modeling to test the proposed hypotheses. Findings The results demonstrate that salespeople’s social media use enhances their social capital with support for direct effects on market knowledge and reputation, and indirect effect on networking. The results also show that the three aspects of social capital drive value cocreation, which enhances cross/upselling performance. Post hoc analysis shows the indirect effects of salesperson’s social media use as well as the interconnected effects of the aspects of social capital on value cocreation. Practical implications The study indicates that salespeople should be encouraged to use social media as a means for enhancing market knowledge and reputation, which can then be leveraged to build networking skills. Providing training to salespeople and coaching them on how to build their social capital is essential if organizations need to capitalize on novel ways to improve the value cocreation performance of their sales teams. Originality/value This study demonstrates how salespeople’s social media use can enhance their social capital, which, in turn, is critical for value cocreation and cross/upselling performance. The proposed framework opens opportunities for future studies to examine the role of salesperson social capital and value cocreation in B2B exchanges.