Holger Geissler studied Psychology in Heidelberg and Mannheim with the main focus on Market and Advertising Psychology. From 1997 to 2000 he worked for Psychonomics as Consultant in the field of loyalty research, branding and product testing. He was from 2000 to 2007 responsible for the division of Online-Research. He was appointed as board member of YouGov Germany in 2008. Today he speaks for YouGov Germany GmbH and is in charge of the research division. From 2004 to 2011 he has been a board member of the German Association of online research (DGOF). He is a assistant professor at the university of applied sciences Cologne in the „Market and media research“ discipline.