Revenue can rise while profits remain flat if advertising, fulfillment, returns and software costs expand at the same pace. It is how much money remains after the entire cost of acquiring, serving and retaining a customer is counted. That shift is forcing merchants to examine practicalways to ecommerce cost optimizeacross the full profit and loss statement rather than making isolated cuts. Reducing an advertising budget by 20%, for example, may improve expenses on paper but hurt contribution margin if the campaigns being eliminated were generating profitable customers. Effective cost optimization is therefore not about making an ecommerce operation as cheap as possible.