The power of social networks stems from their ability to capture real-world phenomena such as collaboration, competition, and partnerships. Social networks provide means for enterprises to capture and expose many informal connections between their stakeholders. In this paper, we discuss how social networks could sustain growth and unfold business opportunities in modern enterprises. Furthermore, we study various types of social networks and investigate metrics that measure their value-added to enterprises. In response to business-oriented social network requirements, we propose a multi-tenant architecture to develop Social-Networks-as-a-Service (SNaaS) and allow efficient use of server resources while reducing maintenance costs and providing a high degree of customization to support each enterprise's requirements. ©2009 IEEE.