Data set has been obtained with the webmaster tool Google Analytics from the period 1st January to 31st December for the year 2011. Moreover, several filters has been applied in data set in order to obtain only instances where bounce rate is lower than 100.00%. This value is the percentage of single-page visits or visits in which the person left your site from the landing page, i.e. we only obtain visits where users have been visited the website more than one seconds. In total the data set is composed by 8,832 instances