YouTube was once a popular video-sharing site built on community. That community is still critical to gaining and keeping a large audience, but heat maps show the YouTube masthead is HAWT around the search field, and YouTube is now the second most-popular search engine after Google. It beats MSN and Yahoo. Or YahooMSN.

ReelSEO has posted a “best of” all of the wisdom for optimizing your videos for search. Read them or be doomed.

Mark Robinson has a wealth of knowledge on this subject, and shares advice from others… like this TubeMogul video about optimizing. Last week I asked TubeMogul to allow us to insert different tags when we upload to various sites (currently tags are entered once for all of the video-sharing sites TubeMogul feeds). Then we can increase our odds by trying different keywords for each video. Not a pure study, since the confounding variable is the website itself, our popularity on that site, and the ability of the video-sharing site to rank at all (some are better than others).

ReelSEO also has a video by Google’s Matthew Liu that gives us some insights on how Google/YouTube ranks videos. They fall into three categories:

1. The obvious: make sure the video is good, short and engages. Tag it appropriately without spamming unrelated keywords.
2. The semi-obvious: engage in the community, encourage comments and ratings.
3. The secret clue: Matthew, at the end, eludes to ensuring that the content is consumed. That suggests two things… be sure it’s short (duh) but also keep the viewer engaged to the end. If your viewers complete the video, the video gets an unseen “attention score” that (I believe) will become the biggest variable. If you have a lot of important text at the end, the viewer will “scrub” the player to reread the text, and that translates to the engine as “yummy content.”

Nalts “Tip of the Day”: Toss in some important text at the end that may require people to pause or replay the last few minutes. Then add a little black to keep them from wandering off to related videos.

Nalts “Bonus Tip of the Day”: In my recent “Killer Caterpillar” video I didn’t pull the typical “please rate” or the ShayCarl “rate 5!” plea. Instead, I simply told viewers that only 1 in 100 actually rate a video. While I don’t expect this ratio to last,  the video got 2,000 ratings on a video seen only 12,000 times. That means 1/6 of the people rated… which is highly unusual. The video is short and took more time than usual, so that also helped… but I thin the high rating ratio contributed to it being the 21st most popular video of the day. Getting ranked as the most popular has become increasingly more difficult since YouTube merged most-popular with most-viewed. And I just spent an hour surfing the most popular to see what I could deduce. It’s primarily driven by a deep fan base: the creators that are deep in the community still rank high, even if the occasional one-hit wonder finds its way.