Koenraad Debackere and Bart Clarysse are at the Vlerick School voor Management, University of Gent, Bellevue 6, B-9050 Gent, Belgium; Michael A Rappa is at the Sloan School of Management, Massachusetts Institute of Technology, 50 Memorial Drive, Cambridge, 02139 MA, USA; and Guido van Hooydonk and R Gevaert are at the Central Library, University of Gent, Rozier, B-8000 Gent, Belgium.
