When I decided to start selling on eBay I was a total novice at sales of any kind.  I had purchased online but had never sold, so why not jump in feet first?  I could answer that question now but not at the time of my jump.  I had no idea what to sell and had never heard of a niche market.  I decided to sell high end watches, but couldn't find a source that was cheap enough to offer them at a good price and still make a profit.  I then found a dropshipper who had beautiful stained glass pieces among other things, and decided that would be a great product.  It is a great product but because of the higher price the listings cost more and not enough sold.  Somewhere, and I have no idea how, I found a supplier that had mainly mens belts and various other leather goods.  I decided to list some of their items and low and behold it wasn't long  that my biggest seller was mens belts.  I still have some unique items in my store but mostly I have belts and other leather goods.  I have learned so much in the time I have had an online store, not  only about the business and belts, but about myself.  This experience has been costly but priceless.