Knowledge is surging as a major resource of sustainable competitive advantage. The Knowledge Community, informal group of individuals that share a common practice, work or interest, is a favourable mechanism to lever knowledge. Organizations are investing, sometimes with little success, in Information Systems supporting the management of knowledge, in order to exploit the knowledge of their experts. Specific Information Systems, the Expert Recommending Services, are conceived to facilitate, in the Knowledge Communities, the identification of the experts that could contribute to solve the business process breakdowns. This research aims at understanding what factors affect the success of this type of Information Systems in order to help the organizations to manage their experts. To attain this aim a multi-method approach has been applied to three different case studies. The main original result is the demonstration that the success of the Expert Recommending Services is influenced by the awareness on the knowledge of the other members of the Knowledge Community.