Social media, especially social network sites (SNS) such as Facebook have grown rapidly in popularity in the last ten years. Facebook now has more than 1.3 billion users. Social media make it easier to maintain connections with strong ties, such as close friends and relatives, but also with weak ties, such as acquaintances or people only met once [1]. They also allow for new connections. Further, social media often blur audience boundaries (audiences are collapsed into one general audience) [2]. To make things even more complex, social media offer public and private communication features that can be further classified, for example, into directed communication (i.e., tagging, liking, or commenting) or more passive communication (i.e., silently consuming what is on your newsfeed) [3]. Unsurprisingly, scholars have thus wondered how social media might impact the nature of interpersonal relationships and ultimately the effects of social capital, i.e., the information and emotional support that people retrieve from their (online or offline) social network.Traditional research on social capital has shown the benefits people can get from their social networks; strong ties provide them with emotional support (hence also bonding capital), and weak ties provide them with non-redundant information and different perspectives (bridging capital) [4,5]. However, these assumptions might no longer hold true on social media where different contexts and audiences collapse, individuals tend to have larger and more heterogeneous networks, and they can communicate in varied and newer ways than previously. This Special Issue brings together papers from different disciplines that focus on generating a current understanding about: (1) the benefits people seek and receive from their social media networks (i.e., informational, instrumental support, and/or emotional support); (2) how tie strength influences which benefits people receive; and (3) the OPEN ACCESS