If you've ever considered implementing a video sitemap, you''ve probably gone throught the same thought process we did. First, "what's a video sitemap?" then "should we have one?" followed by "how come these docs don't make much sense, and why does there seem to be no good information in a Google search?" We spent a while at Mahalo researching to try go figure out if this made sense to build or not. At some point in this process I came across a video which clinched the decision for me. It features Matt Cutts recommending, in no uncertain terms, that all video publisher build video sitemaps.
As a sidenote: If you're considering a video sitemap yourself, I would recommend devoting some time to watching this video from ReelSEO: http://www.reelseo.com/video-xml-sitemaps-video/. It answers a lot of questions that aren't in the documentation or any blog posts I found.
After some looking around, one question still in our minds was: "does all of this still make sense if our videos are hosted on YouTube?" Clearly Google has some sense that our videos exist, as the YouTube version shows up in searches. Yet Google may not be aware of it on the Mahalo.com page we've built for it. In a lot of cases, we believe that the Mahalo.com page is a more valuable experience for a user than simply viewing the video on YouTube, as we are able to provide some additional context to the video within Mahalo.com.
Here's a good example:
Searching for "how to play the chromatic scale on guitar" in google's search returns 3 video links at the top of the search. Two of them are Mahalo's videos on YouTube.
Watching these videos will get the user what they were searching for, but what would be awesome would be for that video link to point to this video on a Mahalo.com course page here: http://www.mahalo.com/learn-to-play-guitar-beginner-course/how-to-play-the-chromatic-scale-on-guitar/. It's good for the user and it's good for Mahalo.
So we built a video sitemap to see if we could start ranking for our videos on our site.
We launched last Thursday, and according to Google Webmaster Tools, the video section of our sitemap has been indexed. We seem to have no errors, and of the 1200 videos listed per page in the sitemap, somewhere between 600 and 1000 are supposedly in the index. I can't seem to find any in Google's video search though, so I'm not sure what's up. I know we do have a few videos which are missing some fields, but that wouldn't explain why none of our videos are showing up in Google's video search.
Hopefully this will resolve itself in the next week or so, but if anyone out there has any suggestions, I'd be happy to hear them. Please email me at firstname.lastname@example.org.