How to Find a Profitable Keyword Niche

"How do I find a profitable keyword niche?" is a question asked by many web authors and bloggers.  The answer isn't that hard, but to find a profitable keyword niche, there is a little online work involved.  Remember that there are thousands of other web and blog creators out there trying to do the same thing, so you will want to make sure you have a strong keyword niche that isn't being used by