The things that people view as problems run the gauntlet of possibilities everything from a hang nail to a golf swing to a chronic disease are people problems that they are looking for help to solve.
A good way to find out what people consider a problem is to visit the online forums. People talk about anything and everything online. They discuss subjects that they wouldnt talk about with their best friends for the simple reason that they can remain anonymous. They look for solutions online for the very same reason. By visiting forums and taking note of what people are most concerned about you can search the Internet for products and services that will help them solve those problems. Gather the information about the topic. Write or have written for you articles about the topic. In this way you can find a topic and build a content-rich website for niche marketing that helps with the problem you have identified and that will serve the needs of people.
An additional way to use forums to help you build a niche market website is to join a forum, identify the problem being most often discussed, post a question that will produce many responses and use those responses to write an e-book on the topic. The fact is that many people will buy an e-book that is filled with information they could actually gather for themselves. They will also purchase e-books that will tell them what other people with the same problem they have think about or are doing about their common problem.