The most sustainable income for any profitable marketplace is dependent on the origin of the traffic. Many marketplaces have failed after major investment because they focused their traffic acquisition on lower price points and neglected higher priced goods. Pay attention to your site architecture also. Be sure to direct shoppers to the best shopping experience by providing clear categories. Specify by skill, design and materials, so that customers who want high-level craftsmanship will connect with those goods. Shoppers seeking a low cost-driven experience can connect with those items efficiently. Avoid universal categories such as shoes, tables, bikes, necklaces...