1. A system configured to assign demographics to a population of data, the system comprising: one or more processing devices configured to: determine a unique client identifier associated with a beacon for web content; send a request including the unique identifier to a source of demographic information; receive information from the source in response to the request including demographic information and a time event associated with user interaction with a resource; determine the potential likelihood that the user generating the beacon is the user that interacted with the resource; assigning the received demographics to the unique client identifier based on the potential likelihood; and a database configured to store a record of the unique client identifier and assigned demographics.