1. A method comprising: instructing, via a first computing device of a monitoring entity, a media provider to embed a tag in media, the tag to cause a device accessing the media to send a message to the monitoring entity when the media is accessed by the device, the message to identify a geographic location of the device; accessing the message with a second computing device of the monitoring entity; identifying, with the second computing device of the monitoring entity, a panelist identifier based on the geographic location of the device; and associating media identifying information included in the message with panelist data associated with the panelist identifier.