1. A method for measuring a user's interaction with third party content, the method comprising: sending a web page in an origin domain to a user device, the web page including a third party link, the third party link directed to a third party page of information in an external domain; detecting a user selection of the third party link on the web page; responsive to the user selection of the third party link: directing the user device away from the origin domain to the third party page in the external domain, the third party page configured to be displayed on the user device, and sending an instruction for the user device to start a timer at the user device; receiving a communication from the user device indicating return to the origin domain; and receiving from the user device information from the timer indicating a duration during which the user device was away from the origin domain as a result of the user selection of the third party link.