Shooting video with a monopod has several benefits.
There are a few very simple techniques that are great for the average photographer who occasionally shoots a video (like me).
Then there are the more sophisticated photogs who want to get professional looking results, without investing in professional dollies, rails, and other shooting rigs that costs thousands of dollars.
I've watched quite a few videos on shooting video with monopod and tripods and played around a bit but am by no means an expert on this one.
1. The primary reason to use a monopod for video work is stability. A steady camera makes watching any video a much better experience.
In the early stages of home videos, many of our videos (mine included) had a lot of camera shake. That was before Image Stabilization, tripods and monopods were employed.
2. Smoother tracking. When attached to a monopod and combined with a long handle and fluid head you can get simply but fluid camera movement that follows a track and adds what I call "visual interest"
The following video show how you get smoother tracking shots by using a monopod for your video clips.
3. A third benefit, of course, is the support of the weight off you hands and arms. Extended video and still photography shoots can give you some muscle fatigue, particularly for larger video camera and DSLRs with long lenses.
Here is an excellent video on Vimeo on shooting video and using a specialized monopod with feet, the Manfrotto 561bvdh: http://vimeo.com/69972568 It's only about 3 minutes long but does a great job of showing you how to get smooth tracking with a monopod.
Using one of the vendors below helps me keep this web site going. Even if you arne't in the market right now for buying a good video monopod, you might consider using Amazon as a good research too.
It makes sense to read reviews of monopods from other buyers-and other products unrelated to photography equipment-because you'll get a good sampling of the experiences of other real people. It won't be the opinion of just reviewer like me.
It is sooooo easy to change the height of you monopoly during a photo shoot. With one hand on your camera, you only need one hand to adjust the one leg of the monopod.
It's one of the overlooked advantages over using a tripod where you usually have to adjust all 3 legs to make a significant change in height.
Although I never used a monopod in the first 30 years of my photography, photography has changed quite a bit and yes, I have too.
Have a blast shooting video with a monopod!