When you start a blog, it is the niche which is the most important aspect of it.
As you may know, it is not simply about starting a blog with any niche you feel like at the moment.
A niche must be selected thinking about it in the long run.
Select a niche in which you at least have an interest to learn more.
If you choose a wrong niche then it can be a matter of great regret for you in the future as you will struggle to find quality article to write and also lose interest in writing the blog after some time.
This is a post that discusses the criteria to choose a niche for a blog.
Your Interest This is the primary and the most crucial factor for choosing a niche.
You do not want a niche where you are dried out of ideas for articles after the first few days and then you want to stop writing altogether.
This kind of feeling comes when you are dead bored of the topics which you are writing about.
So it is suggested that before considering any of the points below - first get a clear idea on what you would like to write about for may be years to come.
Revenue Aspect It is a fact that some niches pay more than the others.
If you feel that for you money does not matter a lot and you are more interested in creating a large base of readers then you can choose any niche that you really love.
But if money is important to you while blogging then do careful research on which are the niches that provide a lot of earning opportunities.
You can check out the Amazon, ClickBank affiliate products which may be you can promote on your niche.
This way you can get an idea on the ways you can earn from your niche.
For example, if you have niche about movies then you can promote CD/DVDs and other entertainment related affiliate programs that are so easily available online today.
But at the same time, if your niche is related to Nuclear Physics I doubt if there is any other way of making money from it except for Google AdSense.
So assess this point carefully.