It seems that the two key words among the well-established professionals who give advice on content writing these days are specialisation and niche. For me, a a bilingual speaker, the word niche is associated with either a small closet where all the preserves and cakes were kept, usually under a key or Niš (same pronunciation), a city further down south in the Balkans.
Ok, I get it, to be able to land a more profitable writing job, you have to know (or learn?) a bit more about the subject you are to write about. It could give the person/company you are writing for a sense of security that you will know what you are talking about.
But then, isn’t your specialty writing itself? You will never know as much about IT as, for example, an IT online company that needs a press release or a brief. If it was only in presenting all they know about the subject, they wouldn’t need you as writer, would they?
Still, you cannot simply produce a rising template, and just simply replace software terminology with bread baking equipment terminology. You have to inform yourself, thoroughly, about the subject, even if you are under pressure of the set timing.
Of course, if you know more about Bonnie ‘Prince’ Billy more than about Bill(y) Gates, you’ll aim to get to write about what you know better. But still, your key special ‘niche’ is writing and you should not shy away from subjects you are not so familiar words.
In essence, for me, the key is in establishing a balance between what you already know and what you have yet to learn. That balance should be the niche.