The recent dramatic increase in the usage and prevalence of social media has led to the creation and sharing of a significant amount of information in various formats such as texts, photos, or videos. When it comes to information consumption, people are not only accessing or appreciating published and shared contents, but also interacting with them by adding comments or pressing the Like button.

In particular, the Like-mediated interactions imply personal preference or interest to the contents. Unlike the friendship- or followship based relationships as illustrated in the above Figure (left), they do not necessarily require a pre-existing relationship, which can be initiated by anyone who accesses and has interests in any types of media posted by others (right). Such expressions of preference from users to contents galore in social media in diverse forms; for example, LIKE in Facebook, +1 in Google+, favorite in Flickr, re-tweet in Twitter, vote in Reddit, or re-pin in Pinterest. In this sense, these micro-expressions are the examples of the content-based relationship, and we call them Like activities in this project.

The "Likes-R-Us" project
at the PIKE research group of Penn State, USA, aims to study various properties and latent relationships found among Like activities and the Like network formed thereof. We study the questions involving the structures, influences, and contexts found in the Like network, and their influences and impacts toward users in social media.