Some embodiments are directed to a system for identifying clusters from a plurality of users using cloud services. A behavior collection module is configured to obtain user preferences for the plurality of users, and an EM module to configured estimate at least one parameter of a distance-based model by the Expectation-Maximization (EM) algorithm for various values of G (number of clusters). A selection module is configured to compute Bayesian Information Criteria (BIC) with the at least one estimated parameter obtained from the EM module for various values of G, compare BICs obtained for various values of G, select the model with the highest BIC as the best model (best model including the plurality of clusters) and use estimated latent variables of the best model to build a classifier. A characterization module is configured to classify each user into a cluster of the best model using the classifier, and to determine ranking preference of each cluster.