As you work on creating your business model you will want to consider how these Ps apply to the online world. Evaluate your business to ensure you are working on each of these P's until you can find improvement. When all four are in the best possible place you have a viable business.
Price: Markespaces are highly competitive because people compare prices quickly. Many customers will instinctively pick the lower price 90% of the time but this isn't always the case. Balancing your price with quality and service to the optimal selling position is helpful.
Product: Because Amazon and Ebay have lots of sharks selling all types of things it can be difficult to find products to sell. Either sell something everyone wants or move into unique and niche products no one else offers.
Promotion: Promoting your product through sales, auctions, descriptions, pictures, and great titles can go a long way in converting people to purchasing your product. As your conversion rate goes up you will notice that accuracy in your information leads to higher customer satisfaction.
Place: Place refers to the place the product places on the marketspace site. If it has the "buy box" or it is ranked on the first page it has a great place. If it is ranked low one will need to improve on customer reviews, price, and overall sales volume.