To receive commissions on sales through the Amazon Web sites, you must be a member of the Associates program. If you are not a member, you can apply at one of the Associates Program sites (listed below) to receive an Associate ID. The Associate ID is the means by which Amazon identifies who has referred a sale to an Amazon Web site and the Associate ID is used to credit commissions.
| Locale | Associates Program Web site |
|---|---|
| US | http://www.amazon.com/associates |
| UK | http://www.amazon.co.uk/associates |
| JP | http://www.amazon.co.jp/associates |
| DE | http://www.amazon.de/partner |
| FR | http://www.amazon.fr/partenaires |
| CA | http://www.amazon.ca/associates |
Note that the Associate ID is site-specific, i.e., an ID for the Japanese site will not credit your commissions if used on the German site. Associate ID values are not validated by Amazon when making operation requests, so incorrect values are not flagged as an error. Incorrectly coded Associate ID values can result in sales commissions that are lower than expected.
Shopping carts are locale-specific, so shopping cart items are not shared between the different locales. If you're offering items from multiple locales, be sure to create one shopping cart per locale for a customer. You also need to provide a way for a customer to purchase the items from each shopping cart.
Some technical considerations to keep in mind are:
An item in a cart may become unavailable between the time when the cart was created and when it is retrieved. Unavailable cart items are automatically changed to saved items when the customer's cart is submitted to Amazon.
Pricing information can also change, literally on a minute-by-minute basis.
Your use of ECS is restricted, as always, to one transaction per second.
Amazon carts with items expire and are deleted if they remain inactive for more than 90 days. Empty carts are deleted after seven days.
An Amazon remote cart can contain no more than 50 items. The 50-item limit is not affected by the quantity of each item (i.e., cart items can have a quantity > 1 and still count as a single item).
Many products have per-item limits, usually around 3 or 5. If users request a higher quantity, ECS will automatically adjust the quantity to the pre-defined limit.
If you try to add a duplicate item to the cart, ECS returns an item_already_in_cart error and the existing item and quantity remain in the cart unchanged.
The HMAC is a security token that you must include along with the CartId in all CartAdd, CartGet, CartModify, and CartClear requests to let Amazon know what cart you want to access. You must always encode any plus sign ("+") characters as %2B in the HMAC value in your cart request operations. The HMAC embedded in the purchase URL is already encoded.
Any application that uses the ECS cart must use the purchase URL to send customers to Amazon when they wish to purchase the contents of their cart.
When working with items in REST requests, the normal practice is to specify Item.1.ASIN, Item.1.Quantity etc. The ECS engine will actually accept anything as the item index value, so Item.foo.Quantity and Item.bar.Action are also valid. This is not recommended practise.
Errors common to all operations can also occur in Cart operations. The cart-specific errors are described below.
Cart-specific errors
| Error code | Description |
|---|---|
AWS.ECommerceService.ItemNotEligibleForCart
|
This message is generated when you try to add an item that cannot be added, such as a parent ASIN. Parent ASINs cannot be purchased directly, you must purchase their variations (children). |
AWS.ECommerceService.InvalidCartId or AWS.ECommerceService.InvalidHMAC
|
Cart may be expired, CartId or HMAC may be corrupted |
AWS.InternalError
|
Can occur for a variety of errors, including invalid CartId or HMAC. This error seems to indicate an Amazon internal error, but may in fact mean that your request was invalid. |
AWS.ECommerceService.ExceededMaximumCartItems
|
You have tried to add more than 50 entries. |
AWS.InvalidParameterCombination
|
Adding an entry (with CartCreate or CartAdd) with BOTH ASIN and OfferListingId generates this error. |
AWS.ECommerceService.;InvalidQuantity
|
Quantity values must be positive integers or zero. |
AWS.ECommerceService.ItemAlreadyInCart
|
When an item already is in the cart, you can modify its quantity, but you cannot add it again. |
AWS.MissingParameters
|
Your request was missing at least one required parameter (e.g., quantity). |
AWS.ECommerceService.;ItemNotAccessible
|
You have specified an item that cannot be purchased through ECS (e.g., a product from a vendor that does not participate in ECS). |
AWS.ParameterOutOfRange
|
The quantity for an item added to the cart must be between 1 and 999. |