Darren from ProBlogger has a good post called How to Choose a Niche Topic for your Blog which is aimed at people trying to decide what subject to blog about.
Here are the questions he asks:
Is the Topic Popular?
Is the Topic one that is growing or shrinking?
What competition is there?
What is the competition neglecting?
Will you have enough Content?
Are there Income Streams on the Topic?
They are all worth considering, but first you need to answer the big one…
Are You Interested in the Topic?
A friend of mine explained it this way recently:
“Probably the best place to start thinking about what your blog should be about is to consider what YOU are about.”
The unspoken truth about blogging is that it isn’t easy, but it becomes virtually impossible if the subject you’ve chosen for your site doesn’t spring from a real part of your life.
You will need to be constantly involved in your topic to become a great blogger and you just can’t fake real involvement and expertise.
Market, Niche & Competition
I think there are a lot of misconceptions about blogging for profit and most of them concern the issue of competition. If there are a lot of blogs in a topic, it may very well mean that it is a thriving market and that there is a lot of money to be made on that topic.
My thought is that in general you will make more money as a mediocre blog in a very profitable niche rather than to be the best blog in the world on a topic that not very many people care about, or that there is no real market for (ie. no products or services or advertisers in that topic). However, that doesn’t mean that there aren’t lucrative opportunities available in certain micro-niche markets where you may be able to dominate the niche (be the big fish in a small pond).
Chose your topic carefully, but do make sure that it is something that you are naturally involved in or have some passion for. There is no room for fakers in blogging.