Your Best might not be Good enough: Ranking in Collaborative Social Search Engines
Henric Johnson, Prantik Bhattacharyya, Shanchan Wu, Jeff Rowe, Karen Zita Haigh, Niklas Lavesson · 2011
—A relevant feature of online social networks like Facebook is the scope for users to share external information from the web with their friends by sharing an URL. The phenomenon of sharing has bridged the web graph with the social network graph and the shared knowledge in ego networks