Some people don't start building their brand because they think it's too competitive.
You always know that where there is a large competition – there's a large demand.
But it is very difficult to get noticed and gain a big market share in a crowded place. For example: look at twitter, it's crowded like shit and to get your tweets in front of people is very hard, because it's too competitive, but on the other side there are a lot of potential readers/buyers. So twitter is a good place to hand around.
Then we have #howtoblog blogs and other content marketing stuff – people are always searching for this kind of stuff.
As a content creator, artist – your best bet is to tap into a market which is under-served. First topics that come into my mind are philosophy and social engineering.
If you go into a market which is over-served – you will find it hard to make an impact, yet it is possible. But it is like really hard.
In essence competition means that people are competing to get your money or attention by every mean possible.
When the competition is big – product prices tend to be lower, and when you're the monopolist in the market – you can rise your prices as much as you want. So monopolies are restricted in capitalism. But there are exceptions.
Before you select your niche – you want to make sure it has enough demand and is not over-populated with other people who are in the same niche.
The other fact: you can create your own niche and make people interested and demanding it. Before there where no planes there was no demand for planes.
Like Steve Jobs said:
You need to create something that people can't resist.
And this is true.
Before you create a post [or something else] be sure that there is or will be a demand.
If you're a writer and writing for the web, telling your personal stories. You should know that if you're not famous your personal life is really not that interesting to people, but when you shift your focus to topics which are trending or hot – the value rises, it doesn't matter how many various topics you'll write, until you're famous most of your stuff will be unnoticed.
So make sure you're building a tribe, an audience of devoted fans.
Competition is not your enemy, competition is your friend.