The most common approach toward e-commerce is to operate a traditional shop. It sends the goods from a warehouse, keeps them in stock and, depending on the whole business model, buys them from a wholesaler or produces them on his or her own. Yet e-commerce comes with multiple alternative business models that challenge traditional ways of doing retail business. Sometimes the challenge is only on transferring a proven and effective business model on-line. That’s exactly the case of a marketplace. To make the matter more clear, we decided to prepare a comprehensive marketplace guide.