A computer-implemented method, performed by a computer system, wherein the computer system comprises a server (101, 201) and an additional server (116, 216), the server including a database (103, 203) having stored thereon a respective reference data set for each of a multiplicity of reference video segments, the computer-implemented method for automatically logging a viewing event on a screen of a television system (108, 208), wherein a memory of the television system has loaded thereon a plurality of contextually targeted display applications (112, 212), each contextually targeted display application having a respective tracking pixel URL address embedded therein, the computer-implemented method comprising the following operations: (a) receiving video fingerprints from the television system at the server, the video fingerprints being derived from television signals for respective portions of a video segment being displayed on the screen of the television system; (b) searching the database to identify a reference data set that most matches the video fingerprint; (c) in response to identification of the matching reference data set in operation (b), identifying a contextually targeted display application which is associated with the matching reference data set; (d) in response to identification of the associated contextually targeted display application in operation (c), sending a signal identifying the associated contextually targeted display application to the television system; (e) sending, to the television system, a trigger signal to the associated contextually target display application to display content on the screen of the television system, the trigger signal also configured to cause the television system to send a request for a tracking pixel from the television system to the additional server using the tracking pixel URL address embedded in the associated contextually targeted display application; (f) receiving the request by the additional server; (g) sending a tracking pixel from the additional server to the television system in response to receipt of the request for a tracking pixel; and (h) logging receipt of the request for a tracking pixel in a memory of the additional server. (a) receiving video fingerprints from the television system at the server, the video fingerprints being derived from television signals for respective portions of a video segment being displayed on the screen of the television system; (b) searching the database to identify a reference data set that most matches the video fingerprint; (c) in response to identification of the matching reference data set in operation (b), identifying a contextually targeted display application which is associated with the matching reference data set; (d) in response to identification of the associated contextually targeted display application in operation (c), sending a signal identifying the associated contextually targeted display application to the television system; (e) sending, to the television system, a trigger signal to the associated contextually target display application to display content on the screen of the television system, the trigger signal also configured to cause the television system to send a request for a tracking pixel from the television system to the additional server using the tracking pixel URL address embedded in the associated contextually targeted display application; (f) receiving the request by the additional server; (g) sending a tracking pixel from the additional server to the television system in response to receipt of the request for a tracking pixel; and (h) logging receipt of the request for a tracking pixel in a memory of the additional server.