The method of claim 1, wherein at least one service request comprises a purchase request, the purchase request including an associated user identifier, the method further comprising: accessing, upon receipt of the purchase request at the server system, user information associated with the user identifier sufficient to charge to an account associated with the user, the purchase price of the product identified by the purchase request; charging the user for the product identified by the purchase request according to the user information; and fulfilling the purchase request based on the user information. view more

A method of processing, in a server system, service requests from a client to the server system through a network, said method comprising the steps of: receiving, from the client, a service request to which a session identifier stored at the client has been appended by the client, wherein communications between the client and server system are according to hypertext transfer protocol; validating the session identifier appended to the service request; and servicing the service request if the appended session identifier is valid. view more

The method of claim 78, further comprising, in the server system: receiving an initial service request from the client; creating, responsive to the initial service request, the session identifier; and returning the session identifier to the client for storage by the client for use in subsequent distinct requests to the server system. view more

A network-based sales system, comprising: at least one buyer computer for operation by a user desiring to buy products; at least one shopping cart computer; and a shopping cart database connected to the shopping cart computer; the buyer computer and the shopping cart computer being interconnected by a public packet switched computer network; the buyer computer being programmed to receive a plurality of requests from a user to add a plurality of respective products to a shopping cart in the shopping cart database, and, in response to the requests to add the products, to send a plurality of respective shopping cart messages over the network to the shopping cart computer each of which comprises a product identifier identifying one of the plurality of products and at least one of which comprises a universal resource locator; the shopping cart computer being programmed to receive the plurality of shopping cart messages, to modify the shopping cart in the shopping cart database to reflect the plurality of requests to add the plurality of products to the shopping cart, and to cause a payment message associated with the shopping cart to be created, the payment message comprising a universal resource locator; and the buyer computer being programmed to receive a request from the user to purchase the plurality of products added to the shopping cart and to cause the payment message to be activated to initiate a payment transaction for the plurality of products added to the shopping cart; the shopping cart being a stored representation of a collection of products, the shopping cart database being a database of stored representations of collections of products, and the shopping cart computer being a computer that modifies the stored representations of collections of products in the database. view more

A network-based sales system, comprising: at least one buyer computer for operation by a user desiring to buy products; at least one shopping cart computer; and a shopping cart database connected to said shopping cart computer; said buyer computer and said shopping cart computer being interconnected by a computer network; said buyer computer being programmed to receive a plurality of requests from a user to add a plurality of respective products to a shopping cart in said shopping cart database, and, in response to said requests to add said products, to send a plurality of respective shopping cart messages to said shopping cart computer each of which comprises a product identifier identifying one of said plurality of products; said shopping cart computer being programmed to receive said plurality of shopping cart messages, to modify said shopping cart in said shopping cart database to reflect said plurality of requests to add said plurality of products to said shopping cart, and to cause a payment message associated with said shopping cart to be created; and said buyer computer being programmed to receive a request from said user to purchase said plurality of products added to said shopping cart and to cause said payment message to be activated to initiate a payment transaction for said plurality of products added to said shopping cart; said shopping cart being a stored representation of a collection of products, said shopping cart database being a database of stored representations of collections of products, and said shopping cart computer being a computer that modifies said stored representations of collections of products in said database. view more

A network-based sales system in accordance with claim 34, wherein said shopping cart computer is programmed to cause said payment message to be created before said buyer computer causes said payment message to be activated.