1. Introduction
An idea of providing a service for reunion of ex-classmates is proved to be a success by resulting in a large number of highly popular web portals with a multitude of users registered at the largest portals. For instance, more than 75 thousands of classmate groups are registered internationally at Yahoo groups
Yahoo Groups: http://groups.yahoo.com
and more than 35 millions of users are registered at a national US and Canadian level (portal Classmates.com uniting graduates of the US and Canadian schools). In relation to other commercial services offered on the Web, the service providing a communication environment for ex-classmates also proved to be promising. For instance, the portal Classmates.com has one of the largest subscriber bases on the Web for paid content and is consistently ranked by Nielsen//Net Ratings as one of the most highly trafficked Web channels.