There has been a great deal of ambiguity and complexity in the relationship between vendor certification and vendor growth in the outsourcing context. In this study, the authors build a competitive mediation model, where they examine both the direct and the indirect effects of vendor certification on vendor growth. Using a combination of primary data (i.e. survey) and secondary data from a sample of 120 IT vendors in India, they find that vendor certification directly helps with vendor growth but it hurts vendor innovation and therefore indirectly hinders vendor growth. They further explore the moderating role of the number of major clients. Results demonstrate that an increase in the number of major clients does not moderate the positive relationship between certification and growth; however, it weakens the negative relationship between certification and innovation. Therefore, a large client base seems to attenuate the dark side of certification in organisational innovation activities.