There are many ways to make money marketing with video but it is always worth making sure that you are operating in a niche that has lots of hungry buyers.
When you have found a niche that fits the bill you should carry out a little research on what words and phrases people within that niche are using in the search engine.
Once you have narrowed down these search terms you will have a good idea for the subject for your video.
You can't really beat YouTube...