1. Sales Management and Chair of the Sales & Marketing Department, Sales & Marketing Department, University of Bochum, Universitätsstraße 150, Bochum, 44780, Germany
2. Faculty of Economics and Business, Professor of Marketing, University of Neuchâtel, A.-L. Breguet 2, Neuchâtel, 2000, Switzerland
3. Sales & Marketing Department, University of Bochum, Universitätsstraße 150, Bochum, 44780, Germany
4. Marketing, University of Houston, C.T. Bauer College of Business, 4750 Calhoun Road, Houston, 77204-6021, TX, USA