1. A computer controlled online transaction mediation method in a computerized telecommunications system, said method comprising: carrying out a transaction, according to a transaction flow formed by steps, between an authorized and authenticated user and a service provider during an active authenticated telecommunications session operated by at least one operator of the computerized telecommunications system, wherein the transaction flow for each transaction comprises at least one transaction rule, wherein each transaction rule can be affected by at least one attribute, and wherein each attribute is selected from the group consisting of content attributes, functional attributes, update attributes and system configuration attributes, and modifying at least one attribute which effects the function and/or the execution order of steps of the transaction flow of the transaction, wherein the authorized and authenticated user, the service provider and the operator are all capable of dynamically modifying said at least one attribute.