I'm a generalist trying to do more specialized freelancing and finding it very difficult. I have a few ideas for niche markets to target but I can't tell which one would be the most viable. I'm curious what rubrics one can use to judge prospective markets.
Specifically, I'm wondering:
How big of a niche is too big and how small of a niche is too small? What specific factors determine this?
Do you determine the market by your price, or determine your price by the market?
I don't know if I can answer all of your questions, but I use the Google Adwords Keyword Tool to find how many monthly Google searches there are for various keywords. For instance, my niche is the Business Plan Executive Summary and I can see how many searches there are for:
Executive Summary Template,
How to Write an Executive Summary,
And other executive summary related keywords,
I can also tell how much competition there is for the various keywords because it shows the average price for a Google Adwords ad. If the competition is high then I look for another niche or keyword.
I usually look for keywords with at least 10,000 searches a month. Depending on your conversion rates you might be able to make a living on a keywords that only have 1,000 searches a month.