TY - RPRT ID - eprints3554 N2 - On social media algorithms for content promotion, accounting for users preferences, might limit the exposure to unsolicited contents. In this work, we study how the same contents (videos) are consumed on different platforms -- i.e. Facebook and YouTube -- over a sample of 12M of users. Our findings show that the same content lead to the formation of echo chambers, irrespective of the online social network and thus of the algorithm for content promotion. Finally, we show that the users' commenting patterns are accurate early predictors for the formation of echo-chambers. M1 - working_paper Y1 - 2016/// EP - 13 AV - public UR - https://arxiv.org/abs/1604.02705 VL - arXiv:1604.02705 A1 - Bessi, Alessandro A1 - Zollo, Fabiana A1 - Del Vicario, Michela A1 - Puliga, Michelangelo A1 - Scala, Antonio A1 - Caldarelli, Guido A1 - Uzzi, Brian A1 - Quattrociocchi, Walter PB - arXiv TI - Users Polarization on Facebook and Youtube ER -