Successful Niche Marketing?

How do I go about identifying profitable niches in Internet Marketing?

We all know some of the popular niches like golf and fly fishing. But these categories are too competitive with incumbents who have already paved the way into the market place.

I realized that it may not be that simple to just get into the common niche markets like this and be successful.

The hurdles are also stacked against you in terms of bidding for PPC adwords (going to be costly) and even if you were to do JVs, I believe these relevant JV partners would already have been approached by earlier incumbents.

Finally, the crux of the matter is also the lack of a frim understanding for most people in terms of the kind of tools that one can use to scan the market place for niche keywords which leads to an understanding of the types of market demand in question.The keyword results is based on what base keyword you type in and hence limited to that one category of choice for eg golf.

the tool to use is called word tracker http://www.wordtracker.com/ — it is supposed to deliver what keywords are actually been searched. it has a limited free version / demo .. they say if you are serious about internet marketing you gotta use this tool.
It is exactly targeted to niche keywords identification.