If you are tracking Ecommerce orders and products on your site, the functions "getItemsSku", "getItemsName" and "getItemsCategory"
will return the list of products purchased on your site, either grouped by Product SKU, Product Name or Product Category. For each name, SKU or category, the following
metrics are returned: Total revenue, Total quantity, average price, average quantity, number of orders (or abandoned carts) containing this product, number of visits on the Product page,
Conversion rate.
By default, these functions return the 'Products purchased'. These functions also accept an optional parameter &abandonedCarts=1.
If the parameter is set, it will instead return the metrics for products that were left in an abandoned cart therefore not purchased.
The API also lets you request overall Goal metrics via the method "get": Conversions, Visits with at least one conversion, Conversion rate and Revenue.
If you wish to request specific metrics about Ecommerce goals, you can set the parameter &idGoal=ecommerceAbandonedCart to get metrics about abandoned carts (including Lost revenue, and number of items left in the cart)
or &idGoal=ecommerceOrder to get metrics about Ecommerce orders (number of orders, visits with an order, subtotal, tax, shipping, discount, revenue, items ordered)
See also the documentation about Tracking Goals in Piwik.