PAPER Utility-based Recommender Systems Using Implicit Utility and Genetic Algorithm

http://www.atlantis-press.com/php/download_paper.php?id=19830

Please see:
Improvement of Matrix Factorization-based Recommender Systems Using Similar User Index
http://onlinedatingsoundbarrier.blogspot.com.ar/2015/04/improvement-of-matrix-factorization.html

Similarity is a word that has different meanings for different persons or companies, it exactly depends on how mathematically is defined.
http://onlinedatingsoundbarrier.blogspot.com.ar/2015/04/paper-hybrid-personalized-recommender.html

In case you had not noticed, recommender systems are morphing to .......... compatibility matching engines, as the same used in the Online Dating Industry for years!
http://onlinedatingsoundbarrier.blogspot.com.ar/2015/03/paper-collaborative-filtering-systems.html

Personality Based Recommender Systems are the next generation of recommender systems because they perform far better than Behavioural ones (past actions and pattern of personal preferences).

If you want to be first in the "personalization arena" == Personality Based Recommender Systems, you should understand the ............ Online Dating Industry first of all!  
http://onlinedatingsoundbarrier.blogspot.com.ar/2015/04/paper-evaluation-of-similarity-functions.html