The following WP eCommerce integration notes are for the WPSSO Core Premium plugin, which includes an integration module to fetch product information from the WP eCommerce plugin. If you use the Free / Standard version of WPSSO Core, you will need to purchase the Premium version of WPSSO Core before using these integration notes.
WPSSO Core Premium will add complete product meta tags for Facebook, Pinterest, and other social websites - if you also need better Schema JSON-LD markup for Google's Rich Results, you should pair the WPSSO Core Premium plugin with its WPSSO Schema JSON-LD Markup add-on. Together, they provide extensive, complete, and correct Schema product markup for Google, including additional product images, product variations, product information (brand, color, condition, EAN, dimensions, GTIN-8/12/13/14, ISBN, material, MPN, size, SKU, weight, etc), product reviews, product ratings, sale prices, pre-tax prices, VAT prices, and much, much more.
The WPSSO Core Premium plugin reads all available product information from WP eCommerce automatically (prices, sku, sales, dimensions, variations, etc.), and can also read these additional WP eCommerce product metadata names if you create them in your WP eCommerce store (note that upper/lower case is important).
Please note the limited selection of product condition values (Damaged, New, Refurbished, or Used), which are determined by Google's Rich Search markup standard -- do not use other values.
If the Google Testing Tool reports that "This Product is missing a global identifier (e.g. isbn, mpn or gtin8)" for your WP eCommerce products, note that the global identifier referred to by Google is not the Schema ‘productID’ property, but a general term used by Google for a missing globally common product identifier like the 'mpn' (aka Manufacturer Part Number) or another globally common product identifier (ISBN, GTIN, etc.).
Unfortunately, the often used product 'sku' (aka Stock Keeping Unit) is a number that changes from one retailer to another, so is not valid as a globally common product identifier. If the Google Testing Tool reports a missing global identifier for your Schema Product markup, make sure you have created one (or more) of the WooCommerce product metadata for the MPN, ISBN, GTIN, etc.
You can customize the default product metadata names that WPSSO Core Premium reads from WP eCommerce under the SSO > Advanced Settings> Editing Pages > Product Attributes tab.
Modifying the default can be useful if you already have one or more existing WP eCommerce product metadata with different names — for example, using the "Colour" metadata name instead of "Color". ;-)
The WPSSO Core Premium plugin provides WP eCommerce product prices in meta tags and Schema markup without tax by default. If you prefer your meta tags and Schema markup to include product prices with VAT, you can define the following constant in your wp-config.php file:
define( 'WPSSO_PRODUCT_PRICE_INCLUDE_VAT', true );