Abstract: In accordance with a method for determining a likelihood that two or more communication devices are associated with a common user, clickstream data from a plurality of clickstream events is received from each of a plurality of communication devices in response to a web page being loaded by each of the communication devices. The clickstream events received over a period of time are arranged into a datastream such that each of the datastreams contains clickstream events from only a single communication device. Based on the clickstream data in the clickstream events, potentially matching pairs of datastreams are identified that contain clickstream events from a common user using different communication devices. A statistical analysis is performed on the potentially matching pairs of datastreams in accordance with a statistical model in order to determine a likelihood that each of the potentially matching pairs of datastreams contain clickstream events from a common user.