Abstract: Nowadays consumers spend a significant amount of time on social networks and enterprises have followed them and have built their presence online in order to make themselves more visible. The shift from real-world business and marketing to the online environment has led to a series of new ways of doing business, implementing marketing strategies and thinking advertising. As enterprises started competing on social media platforms, unfair competition slipped in. The article analyses the specific manner in which unfair commercial practices materialize themselves on social media platforms and it focuses on the main types of unfair competition namely aggressive commercial practices and misleading commercial practices. In addition, there will also be considered and discussed the unfair commercial practices that are intended to prejudice other traders.  The analysis takes into consideration mainly the features and the activity that is possible on the social media platform Facebook as it is the largest at the moment and it raises stringent issues regarding the protection of consumers and even the protection of enterprises. 

Keywords: unfair commercial practices; social media; advertising.