We have been looking for this document on the Web. We think we have found the following, freely available version(s) of it: http://www.cs.virginia.edu/~sullivan/EDSER-1/PositionPapers/succi.pdfhttp://www.unibz.it/web4archiv/objects/pdf/cs_library/2/UnderstandingtheRoleofNetworkExternalitiesinSoftwareSystems.pdfFor further information about this item go to:http://doi.acm.org/10.1145/338183.338194