This might be defensive in a way? This is Roku, a maker of media players, patenting a method where a TV would detect the connected player stopped playing and inserts an ad.

Being that Roku makes the media device, it'd be trivial for them to insert an ad without any of this "detect a pause in content" hackery. So I'm going to guess that the point here is actually preventing TV manufacturers from playing ads over Roku's stuff by patenting this themselves first.

Also, sheesh, the patent system is a plague that should be done away with. This is a technically completely straightforward process. There's nothing innovative being done here.