Niche –– a focus that differentiates you from others in your field.
If you were arrested and charged with a capital felony, would you want a ‘general’ lawyer to represent you or a lawyer who specializes in ‘criminal defense’ law? I rest my case (no pun intended).
Being a specialist in some aspect of what you do positions you relative to other providers in your field. All things being equal, it helps you ‘stand out’ as a Preferred Provider of your problem-solving expertise.
Specialists are more attractive than generalists. Being a ‘specialist’ positions you as a preferred provider in the eyes of prospective clients.