Social media act as primary means of connection between the stake-holding public and varied enterprises, including nonprofit entities. The media also have great potency to assist nonprofit organizations (NPOs) to deliver real-time transparency to the public. While prior studies have assessed how NPO online accountability is discharged through organization website, fewer ones discussed on social media usage to deliver online accountability. This study, therefore, aims to find out how social media act as online accountability channels for NPOs and observe which social media is the most effective in performing such an objective. The study follows a qualitative case study approach on a nonprofit Indonesian humanitarian organization. While the data was collected through a document review, semi-structured interviews, and content analysis of massive social media statistical data (including 18,929 posts made by the NPO from January 1, 2012 to August 28, 2020). The data was subsequently analyzed through the use of the thematic method. Using NPO accountability framework developed from former literature, it is found that NPOs can fulfill various dimensions of accountability through social media: formal-informal and upward-downward. Nonetheless, their current use of social media is still restricted to short-term rather than strategic accountability. In terms of effectiveness, Facebook followed by Instagram surpassed other media in terms of attracting fans, engagement, and total reactions-comments-shares. This study offers several implications for the management of NPOs by outlining a framework of optimizing social media for discharging online accountability as well as further research agendas to scholars interested in the subject.

社交媒体是利益相关的公众与包括非营利实体在内的各种企业之间建立联系的主要手段。媒体还具有很大的潜力来协助非营利组织（NPO）向公众提供实时透明性。尽管先前的研究已经评估了NPO在线问责制如何通过组织网站来执行，但有关社交媒体使用以提供在线问责制的讨论较少。因此，本研究旨在发现社交媒体如何充当非营利组织的在线问责渠道，并观察哪种社交媒体最有效地实现了这一目标。该研究遵循了对一家非营利性印尼人道主义组织的定性案例研究方法。虽然数据是通过文档审查，半结构化访谈收集的，以及大量社交媒体统计数据的内容分析（包括NPO从2012年1月1日至2020年8月28日发布的18,929个帖子）。随后通过专题方法对数据进行了分析。使用从以前的文献发展而来的NPO问责框架，我们发现NPO可以通过社交媒体实现问责制的各个方面：正式-非正式和向上-向下。尽管如此，他们目前对社交媒体的使用仍仅限于短期而非战略问责制。在有效性方面，Facebook和Instagram紧随其后，在吸引粉丝，参与度和总反应-评论-份额方面超过了其他媒体。