PurposeThe purpose of this paper is to investigate how four enterprise social media (ESM) affordances (visibility, association, editability and persistence) affect social network ties (instrumental and expressive), which, in turn, influence the in-role and innovative job performance of employees.Design/methodology/approachA survey of 251 ESM users in the workplace in China was conducted.FindingsAll four affordances are positively associated with instrumental ties, yet only the association and editability affordances are positively related to expressive ties. Although instrumental and expressive ties are positively related to in-role and innovative job performance, instrumental ties exert stronger effects on in-role job performance, whereas expressive ties show stronger effects on innovative job performance.Research limitations/implicationsFirst, additional relevant affordances should be included in an expanded model. Second, future research could examine how patterns of affordances use (unrelated, or hierarchically or sequentially related) affect organizational network ties. Third, there are likely (many) other exogenous factors affecting the model’s relationships. Fourth, the data collected are self-reported.Practical implicationsThis study advances the theoretical understanding of the role of ESM affordances in the workplace, especially through their influences on network ties. The findings can guide organizations on how to emphasize ESM affordances to foster instrumental and expressive ties to improve the job performance of employees.Originality/valueFirst, it provides novel views on affordance theory in ESM contexts by empirically testing four central affordances, thereby further providing preliminary evidence for prior theoretical propositions by confirming that social media affordances might be associated with or influence relational ties. Second, the study integrates an affordance lens and a social network perspective to investigate employees’ perceived performance behavior. Including social network ties can offer a more detailed understanding of the underlying processes of how ESM affordances can and do affect job performance. Third, it supports the validity of distinguishing instrumental and expressive ties in ESM contexts, thus offering a possible explanation for the inconsistencies in prior research on the impact of social networks on employee outcomes. Finally, it also shows how two kinds of organizational performance (in-role and innovative) are somewhat differentially influenced by affordances and network ties.