Brown, Chloë, et al. "The importance of being placefriends: discovering location-focused online communities." Proceedings of the 2012 ACM workshop on Workshop on online social networks. 2012.

This study introduces a novel approach to identifying place-focused communities within online social networks by leveraging check-in data from location-sharing services like Foursquare, Gowalla, and Facebook Places. By annotating the edges of the social graph with check-in information, the research demonstrates the ability to discern groups of friends who frequently meet in person. This method offers potential improvements for online social services, including enhanced privacy management, more accurate friend recommendations, and efficient contact grouping akin to Google+ circles. The effectiveness of this approach is validated using data from two online social networks, showcasing its potential to benefit both users and platform providers by facilitating more meaningful social connections based on physical world interactions.