1. A method for an integrated retailer website to sell products over a communication network to a customer where order fulfillment operations are performed by a third party, comprising steps of: providing a common catalog of products through an extended markup language (XML) export function to the retailer website; and utilizing a retail web service operatively configured to provide fulfillment functions based on information in the common catalog through a representational state transfer type architecture such that the fulfillment functions are implemented as hypertext transfer protocol (HTTP) GET and POST operations on universal resource locations (URLs) that represent business resources.