niche: [nich] noun
relating to or aimed at a small specialized group or market
When you focus on a niche market you are addressing the need for a product that is not necessarily being addressed by other sellers. Think of it as a small but profitable segment of the Auction House suitable for focused attention by a seller – you.
There is not a niche video for Leather. I’ve heard many other MGB’ers talk of the profit they make from Leathers.