One of our clients sells a variety of products from their own custom built e-commerce web site which they host locally at their company office. However, the ultimate fulfillment of the order is done from SalesForce, having been manually entered by an employee once an order is received on their ordering site. This resulted in many problems, the manual work, duplication of effort, mistakes, not to mention the customer contacts in the e-commerce site were different in each system, even with different usernames and passwords.
We worked with the client to add 2-way replication of data from the e-commerce site to SalesForce, and vice versa, via custom functions and Salesforce API Callouts. So when an order was received in the e-commerce site, all the order data was replicated to the proper contacts, campaigns and opportunities within SalesForce. And if any SalesForce data was changed, say in a contact, that information was replicated instantly to the e-commerce site, keeping them in sync. We also instituted Single Sign-On for both systems utilizing a secure OAuth mechanism, so not only were the usernames and passwords the same for both systems, logging into one of them reduced the need to re-prompt a user for credentials when travelling from one system to another.
The system was further customized to allow for a simple XML configuration script which defined which items in which systems went where when replicating, in the event that the schema on either system changed, it would not require developer intervention.
We routinely work with SalesForce customization and interactivity, and this project saved the client countless hours of duplication and increased accuracy and response times for delivery by an order of magnitude.