Web 2.0 technologies require enterprises to utilize them in sharing information, promoting creativity, and enhancing communication capabilities with their internal and external customers. Many enterprises have proactively considered adoption and use of social network service (SNS) as business communication tools. However, there have been few studies about the use of SNS by Korean companies; its benefits and characteristics of successful use of SNS in the context of business communication. This study describes the background of in-house SNS, its characteristics and value of SNS; addresses the current challenges some companies are facing in application of in-house SNS; and discusses the ways that such challenges can be effectively taken care of. This study introduces four business cases where the firms use in-house SNS with different goals and activities. Finally, this study presents the implications for enterprises considering the adoption of in-house SNS as well as the issues related to its successful implementation.