Amazon.com on Thursday introduced a new way for online merchants to leverage Amazon's infrastructure to ship physical products.

"The Amazon Fulfillment Web Service (Amazon FWS) allows merchants to tap in to Amazon's network of fulfillment centers and our expertise in logistics," said Amazon Web Services evangelist Jeff Barr in a blog post. "Merchants can store their own products to our fulfillment centers and then, using a simple Web service interface, fulfill orders for the products."

The idea, Barr explained, is to be able to ship a product with a simple Web service call.

By making it possible for merchants to further automate their e-commerce and fulfillment efforts, Amazon is demonstrating its commitment to selling "muck," as CEO Jeff Bezos has referred to his company's e-commerce infrastructure.

Amazon FWS is designed to complement Fulfillment By Amazon (FBA), the fulfillment service Amazon has offered since 2006, by making the fulfillment process accessible programmatically. Amazon also maintains a separate fulfillment program called Amazon Advantage, which allows content publishers to send Amazon music, books, and videos for sale on consignment, with a 55% fee.

FWS is free, but fees are charged for goods stored and shipped through FBA. The fee is a total of per-order, per-unit, and per-pound charges. The fulfillment charge for a book or CD ordered through Amazon, weighing less than a pound, and retailing for less than $25, for example, would be 90 cents. The same item ordered through a third-party site using Amazon's APIs would be $2.95.

There's also a 45-cents-per-cubic-foot goods storage charge that increases to 60 cents per cubic foot during the holiday season, from October through December.

FWS offers two sets of APIs for inbound and outbound items. Using the getInboundShipmentPreview function, for example, merchants can locate nearby Amazon fulfillment centers. The putInboundShipment function alerts Amazon to expect an inbound item, and the setInboundShipmentStatus function tells Amazon that the shipment is on its way. Other functions provide a way to programmatically tell Amazon to ship orders, cancel them, or return information about order status.

Amazon Web Services consists of a variety of services, including Amazon Associates Web Service (formerly Amazon ECS), Amazon Elastic Compute Cloud (Beta), Amazon Flexible Payments Service (Beta), Amazon Mechanical Turk (Beta), Amazon Simple Storage Service, Amazon Simple Queue Service, Alexa Site Thumbnail, Alexa Top Sites, Alexa Web Information Service, Alexa Web Search, Amazon DevPay (Beta), and Amazon SimpleDB (Beta).