I'll give you an example of my own search, and we'll get some discussion going about figuring out what you really want to be doing.

My doctorate is in engineering, though I have never actually engineered anything. In the first ten years after I finished college I was a computer guy when there weren't many around. I was with two large corporations, a software startup, two universities, and in state government.

For the next twenty years, I owned a pretty successful business. While I owned it, it left me free enough to hold elective office, serve as executive director of two non-profits, do some consulting and teach as an adjunct at just about every college in the area.

When I got a nice offer to buy my business, I felt the time was right. I had nothing in mind that I might do, and was at that awkward age of (55) too young to retire, but too old and out of practice to take a full-time job. 

Since then, I have been interim president of an economic development agency, and a college professor, including a term as a visiting scholar in New York. I also wrote two textbooks with major publishers (one on entrepreneurship, the other on raising capital). See my entrepreneur site for more detail.

While I was at it, I picked up an MBA, 37 years after I earned a Ph.D. I had worked in and taught business, so I thought it was about time I earned a degree in business.

So, where's the niche in all that?

Do you see any common thread running through those experiences?

My conclusion is that I am an information addict. I love to soak up information on subjects that fascinate me (and there are quite a few), achieve some mastery of those subjects, then write and teach about them. This motivates me to stay current and at the leading edge.

Before blogs became all the rage, I had heard enough rumblings about them to know I had better get one started, and chose politics as the topic. When I decided to get involved in this field, I started an Internet marketing blog to point out some of the extreme behavior that gives this form a bad reputation.

So, where are we now?

The story is to demonstrate that It is possible for a niche to be an intangible. But do not become an Internet marketer; the field is already too crowded.

It may take some real introspection to figure out what we really enjoy doing  professionally. When we make a choice, we will understand that we may not  enjoy every task, but we won't sign on for anything that is basically unpleasant, just to make money, now would we?

Now, we get our first homework assignment. First, read some more about niche marketing, and begin to generate some ideas for yourself. Try:

http://www.google.com/search?q=niche+marketing