If you're looking to invest in a niche e-commerce stock, Etsy is hard to ignore.Even with the advent of smartphones, digital payments, and the internet, brick-and-mortar shopping still represents 84% of overall retail spending in the U.S. There's still a lot of room for online shopping to continue rising, especially in less developed parts of the world.Etsy (ETSY -2.76%) is one such option when looking to put money to work to benefit from this trend. Before you decide to buy this e-commerce stock, here are ...