|A unique identifier of the product (e.g. a SKU)
|The name of the product
|An array of categories the product belongs to
|The price of a product in cents
|The URL of an image or thumbnail of the product
|The URL of the product page on your site
|The current stock value of the product
|A string representing the date on which the product expires
expiration_datefield is stored as a proper datetime and is simply used for audience segmenting and display purposes.
Any additional params will be treated as strings and added to the
metadatafield of the product.