In epistemic communities, people are said to be selected on their contribution in knowledge to the project (articles, codes, etc.). However, the socialization process is an important factor for inclusion, sustainability as a contributor, and promotion. Finally, what matters for being promoted? Being a good contributor? Being a good animator? Knowing the boss? We explore this question by looking at the election process for administrators in the English Wikipedia. We used the candidates' revisions and/or social attributes to construct a predictive model of promotion success, based on the candidates' past behavior and a random forest algorithm. Our model explains 78% of the results, which is better than the former models. It also helps to refine the explanation of the election process.