1. Survey Design and Methodology, GESIS – Leibniz-Institute for the Social Sciences, Mannheim, Germany
2. Free University Berlin, Institute for Media and Communication Studies, Berlin, Germany, Weizenbaum Institute for the Networked Society, Berlin
3. Institute of Communication and Media Studies, Leipzig University, Leipzig, Germany
4. Professional Communication in Electronic Media/Social Media, Universität Duisburg-Essen, Duisburg, Germany
5. Faculty of Business Administration and Economics, Paderborn University, Paderborn, Germany