Let's put jewelry vendors in the spotlight for a moment. Most of us who are in the "Vendor's World" know, you will get more jewelry vendors then any other type of vendor, true? If you fall in this category, knowing your niche market can and will be helpful for you.
You can decide to sell jewelry that consists of birthstones or maybe you can sell jewelry that is inspired by animals (cat pendants, chains, charms, etc...). Whatever jewelry you sell, be sure to sell something different than your competition. Know what people are compelled to buy. Zodiac jewelry, Birthstone Jewelry, Bling-Bling, pearls, etc....
After you have identified what appeals to the masses, build on this niche. Find different types of jewelry within your niche market i.e. chokers, long chains, interchangeable jewelry, matching sets, etc... Find your niche and stick to it. As you build, you will begin to expand to different areas.
This same concept can be applied to many other businesses even if you are a tax preparer. If most offices close 9 months out of the year, find a reason to stay open at least 10 months out of the year. If the other tax preparers are preparing simple taxes, build your niche on business taxes and chose your genre (corporate businesses, small businesses, entrepreneurs, government, etc...) Find something different and make it work for you!