Juggling videos are classified based on several issues but they all boil down to how interesting/entertaining most jugglers will find them. Production quality obviously helps. Doing something rare, difficult, or just novel will likely increase the size of the audience that will enjoy a given video.
Highly Recommended -- This is for videos that we feel most jugglers would really want to see. Given the number of videos, a target of about one "highly recommended" video per day is our goal.
Worth Seeing -- Most jugglers will probably enjoy these videos. If you have the time, watch it.
Limitted Audience -- These are for videos that may still be quite good/fun, but are something many jugglers have likely already seen a few times. Almost all videos will be enjoyed by some jugglers, the preview screen and title will give hints to who will like it.
Video length can effect the likely appeal of videos. A short video has an advantage that not much time is invested. It makes it easier to have a high level-of-awesomeness per second. But short videos also have a higher "click overhead" and may not set the mood.
There is no need to classify every video.
We take a fairly wide view of what is juggling. Poi, acro, or even a cool frisbee routine can be considered "juggling". What isn't juggling is "juggling a busy life" and video game "juggling" (a fighting technique). Soccer juggling (one soccer ball) and golf club juggling we don't normally consider "juggling" unless we just think the video fun enough.