while negative operating cycles offered one important source of advantage over brick and mortar competitors, Amazon sought to reap even larger efficiencies from its comparative lack of physical infrastructure. The business model, as described in Amazon's prospectus, called for a minimum of bricks. The company sources product from a network of book distributors and publishers. The company carries minimal inventory and relies to a large extent on rapid fulfillment from major distributors and wholesales which carry a broad selection of titles