An article on the use of web services in enterprise integration has the following interesting snippet about Amazon:
An example of the business value of Web services is Amazon.com. Amazon.com is using Web services to make its system capabilities available to others who in turn use Amazon to sell products to their mutual benefit. It’s give to get, and is an argument for companies to look at Web services not just as a tactical alternative to application integration but as a strategic initiative. In 2002, Amazon generated about 6.2% of their revenues, or $246 million, by using Web services to become an e-commerce platform. [Web Services Journal]
