1. An automated computer system configured to determine and assign demographics to electronic data based on access of an online resource by a client device, the system comprising: a non-transitory storage device storing an application including instructions; one or more processing devices operable to access the application and execute the instructions, the instructions causing the one or more processing devices to: access a message automatically generated when web content associated with a beacon is accessed by the client device; determine a unique client identifier accompanying the message; determine a time indicating when the message was received, transmitted, or created; request information from a cookie exchange associated with the unique client identifier; receive, in response to the request, information from the cookie exchange including a time of an event indicating when a resource was accessed by the client device and demographic data associated with the access of the resource; determine the potential likelihood that a user associated with generation of the message is a same user who accessed the resource based on the determined time of the message and the time of the event associated with access of the resource; assign the received demographic information to the unique client identifier based on the potential likelihood, such that subsequent messages automatically generated when web content associated with the beacon is accessed comprise the demographic information; and store a record of the unique client identifier and assigned demographic information in a database associated with the client device.