Video search engine optimization has been a hot topic since the launch of Google Universal Search. A Google Groups thread I have been tracking for some time, gives us some insight into how to improve the visibility of your videos in Google search.
If you take a look at the Google Video Sitemap specification, you will notice that a <video:content_loc> tag is optional, not required, for Google to index and list your video. But that isn't always the case, based on this Google Groups thread.
One video producer couldn't figure out why his video content wasn't being indexed, After some time, JohnMu posted the following answer:
I double checked with the video team on this and it appears that specifying a valid video:content_loc for your URLs would really help us in recognizing the videos directly. In general, this tag is optional, but in certain situations we may not be able to find the content easily and therefore it would help for you to specify it. I'll follow up with the video team once you have it there to make sure other issues don't come up.
So, it is optional in some situations but in this situation it is necessary. I am not sure why this situation it is a requirement. If it is ever a requirement, it should tell you in which cases it would be required but it doesn't. To be fair, Google does say:
Since each video is uniquely identified by its content URL (the location of the actual video file) or, if a content URL is not present, a player URL (a URL pointing to a player for the video), we strongly recommend including either the
or tags. If these tags are omitted and we can't find this information, we'll be unable to index your video.
But for this video producer, it really doesn't help much because his videos are pay-per-view. Maybe there is a work around, John is looking into a solution for this video producer. I am thinking, a First-Click-Free solution for Video Content?
Forum discussion at Google Groups.