In the world of e-commerce, Amazon isn't the only business generating serious returns for its shareholders.Investors might believe that the world of online retail is dominated only by Amazon. But there are other businesses that are finding remarkable success in the market. Shopify (SHOP -7.85%) deserves some attention, as it provides a vast ecosystem of products and services that help companies start and grow.The business has definitely taken investors on a volatile journey. But disciplined shareholders who ...