## 1 Introduction  
Information and communication technologies have changed the process of governing in the world. Governments worldwide have responded to the challenging opportunities offered by e-government in order to form an administration that engages with citizens and consults them, to meet the increasing demands and expectations of citizens, to overcome the major barriers of reduced public budgets and to provide value-added services to their citizens [1; 2; 3]. An open government is committed to \"bridging the gap\" between the government and its citizens [2] and to the principles of \"transparency, public participation, and collaboration\" [4]. Nowadays, governments have started embodying social media technologies and applications in their e-government strategies in an attempt to maximize the Web 2.0 benefits and to keep up with current trends [5]. The use of social media by public agencies may enhance participation, transparency, accountability, integration, communication and collaboration, promote civic engagement, revitalize dialogue between citizens and government and speed up the pace of innovation [6; 7; 8]. Twitter is a microblogging service that allows users to share information via short messages with a maximum of 140 characters in length and to answer the questions: \"What's happening?\", previously, and \"What are you doing now?\" [9; 10]. The restricted size of the text implies that tweets may not necessarily contain well-formed ideas or developed context, but they are complete enough to be coherent [11]. Moreover, the quick nature of Twitter results in a constantly updated stream of short messages ranging from breaking news, real-life events, like revolutions and natural disasters, global discussions, shared links and thoughts on life. People use Twitter to ask for directions, support, advice, to communicate, to ask questions and to validate ideas by discussing them with others. Thus, Twitter allows for large quantities of concise and diverse concepts to evolve [11; 12; 13; 14]. Twitter affords a variety of functions; users can set their updates to private, or they can allow the entire cyberspace area of Twitter, the \"Twitterverse\", to view their pages [15]. The vast majority of Twitter accounts are public [16]. Users may also choose to follow other users; thus, the structure of followers forms a large network [17]. However, the act of \"following\" users on Twitter is not mutual. An \"asymmetric\" model of human relationships exists [18]. In this vein, Twitter does not properly exhibit a \"traditional\" social network structure [14]. In the Twitter vocabulary, to write a tweet addressing a specific user is called a mention, _@_reply is a tweet directed at a certain user, RT stands for retweet and a \"\(\#\)\" followed by a word represents a hashtag. Retweets allow users to rebroadcast content generated by others, thereby raising the content's visibility [19], while hashtags are grouping tweets by topic, allowing users to annotate tweets with metadata [20]. According to [PERSON] _et al._[10], users are connected in an implicit or explicit manner via retweets, _@_hashtags, _@_replies and follower relationships. Moreover, third parties offer services that add functionality to the Twitter site, such as the ability to donate money or rank the influence of its users [21]. Twitter is one of the most used social media applications by government agencies, public affairs practitioners and politicians [22]. Regarding e-government, Greece lags behind other EU nations [23] and also in global terms. The United Nations' e-government survey [24] ranked Greece's e-government project as number 37 worldwide; Greece increased its world ranking from the 41 st position in 2010. Greece is now included in the list of countries that provide a statement \"follow us on Facebook or Twitter\" at government websites [24]. The paper aims to investigate how followers distribute among e-government accounts and to record citizens' preferences regarding which Twitter accounts they follow.