1. A collaborative Business Intelligence (BI) system comprising pages based on said BI system data, comprising: at least one processing unit; at least one BI related content storage communicating with said at least one processing unit for storing an online analytical processing (OLAP) database; a user interface which allows displaying a page comprising a view of at least one OLAP cube from said OLAP database to a user of a plurality of users of the BI system; an OLAP semantics module adapted to deduce automatically from semantics analysis of user data in said at least one OLAP cube an implicit relevancy of each of at least some of said plurality of users for a collaboration session about said at least one OLAP cube with said user; a relevancy search engine which selects the most relevant users from said plurality of users for said displayed page according to a relevancy number and according to user data of each of said plurality of users, said user data comprises a member of a group consisting of: user fields of interests, user discussions pertaining to said page, and user comments entered in the context of said page, wherein said relevancy number is calculated according to a weighted combination of at least tag matching, usage of said displayed page, said implicit relevancy and user ranking of said displayed page; and a collaboration platform communicating with said at least one processing unit for presenting a new discussion indication in a discussion pane and initiating said collaboration session about said at least one OLAP cube between said user and at least one of said most relevant users in response to a user input; and a network interface communicating with said at least one processing unit.