There is a new page dedicated to example code in multiple languages that include C#, PHP, and Perl.
For the function, "AddUser", the Email, First Name, and Last Name are all optional. Only the CustomerID is required.
The function "DeleteProduct" removes a Product from being viewed by the Customer. It does not however completely delete it from their or our records. When a Product is added it counts as a purchase. This just hides the video from the Customer.
The parameter "productKey" has been changed to "itemKey" in the function, "AddProduct".