A broad niche is a large group of people that share a common interest, according to Finding Niches. For example, aficionados of automobiles, gaming, photography or running are broad niches. There are narrower areas of interest within these broad niches, which are called narrow niches.
Broad and narrow niches are terms used by Internet marketers to describe different approaches to targeting customers. A broad niche approach targets a large audience, whereas a narrow niche is more specialized. Benefits of targeting a broad niche include a broader appeal and the possibility of reaching a greater number of customers. It is also a convenient starting point for finding narrow niches.