When not considering the campaign of Barack Obama, the best example of using social media in parliamentary election campaign was the campaign presented by the SaS (Freedom and Solidarity) political party. It has signiﬁcantly accelerated the setting of social media as tools of the political marketing in the environment of the Slovak political scene. Since the parliamentary elections in June 2010 a sharp increase of the politicians´ interests in social media, especially in Facebook and YouTube, can be seen. This study explores the potential of social media and identiﬁ es key factors of a successful communication. The core of the study is a detailed analysis of the activities of candidates for mayors in municipal elections in 2010. It points out that the main problems of using social media are the ignorance of the social media speciﬁ cs and application of traditional practices and attitudes that do not work in social media.