Amazon is one of the best resources to use; you can use them to see what is selling and what is not. After doing a lot of trial and error I have found that if you search for something on Amazon, and there are over 10 products selling for that search term, you’ll have a good starting point for writing your articles.
Example: The search for how to fish in a pond brings up 146 results. This is my actual competition which shows me there is a market for products in that niche.
Next, and narrow my results for kindle books. This will show me my true competition. After reviewing the books available that looks like there are no kindle books or articles on this subject. Perfect, this continues to be one of my best Sellers to.
This is one of the easiest and fastest ways to determine what a good subject to write will be about. Though it is a great starting point, this is not the end either.