3rd ACM Conference on Recommender Systems 2009 (RecSys '09) : New York, New York, USA 22-25 October 2009 - ACM Conference on Recommender Systems; ACM Special Interest Group on the Social and Behavioral Science of Computing; Association for Computing Machinery. Special Interest Group on Information Retrieval; ACM SIGWEB; Association for Computing Machinery. Special Interest Group on Knowledge Discovery & Data Mining; SIGART (Association for Computing Machinery, 2009)