Purpose – The purpose of this study is to clarify business-to-business (B2B) customers’ behavior regarding their social media use for B2B purposes and the antecedents of this behavior in the industrial marketing setting. It explores the influence of corporate culture, colleagues’ support and personal and psychological factors on customer behavior toward social media business use. Design/methodology/approach – The authors conducted an online questionnaire survey among key customer accounts of an information technology service company (N = 82). Partial least squares (PLS) path modeling was utilized to analyze the relationship between the dependent variable (social media business use) and the independent variables. Findings – Results show that private social media usage has the most significant relationship with the social media business use. Colleagues at work are also supporting B2B social media use and personal characteristics are also of importance. Surprisingly, perception of usability of social media for B2B use did not explain social media business use within our sample. Research limitations/implications – The chosen methodology, sampling frame and sample size may limit generalizability. Therefore, researchers are encouraged to test the proposed hypothesis in other settings, particularly as the diffusion of B2B social media increases. Practical implications – The paper provides insights into how marketing managers can make an impact with their social media marketing. For example, when planning social media activities, companies need to consider which social media services could serve their marketing and communication targets and would reach the customers. Originality/value – Studies related to social media in B2B, especially from a customer’s perspective, are still limited, and the authors do not know how customer firms value industrial marketing activities in social media. This novel paper provides insights into managers’ reasons for using social media and gives guidelines for B2B marketers on how to conduct social media marketing in the future.