1. A method for identifying potential churning telephony customers, said method comprising the steps of: obtaining data pertaining to telephone calls between a plurality of customers; forming a graph having a plurality of nodes representing said customers and a plurality of edges representing said telephone calls between said customers; denoting a sub-set of said customers as previously churned customers; and applying a spreading activation model to said graph to identify, based on said graph and said previously churned customers, said potential churning customers.