Purpose This study recognizes service as the majority contributor to global and US gross domestic product and the importance of innovation speed to service innovation. Generating innovative products and services at a faster rate generates advantages for business-to-business (B2B) service organizations in keeping up with and moving ahead of rivals. This study aims to introduce the concept of capacity for social exchange (CSE) in buyer–supplier relationships, which reflects the degree to which individuals possess competencies that enable the exchange of information, and this study also explores how CSE affects knowledge sharing and innovation speed within a supply chain organization. Design/methodology/approach The sampling frame of this research consisted of service businesses in the USA. The data were collected through Zoomerang, an online survey research firm where the B2B panel of Zoomerang formed the sampling frame. The data was collected from 264 B2B service sector executives. Findings The key findings are as follows: CSE facilitates knowledge sharing; knowledge sharing is positively related to innovation speed; and the relationship between CSE and innovation speed is fully mediated by knowledge sharing. Additional analysis reveals that knowledge channels which are designed as boundary-spanning strategies used to transfer and create knowledge between business units, directly increase – and positively moderate – the relationship between CSE and innovation speed. Originality/value This study addresses the gap in literature focused on micro-level influencers on innovation. This study sets out by presenting the concept of CSE, and this study addresses limitations in prior work by examining the research questions.