What is the difference between “splitting” and “flattening” variable products?

Let’s say you have 5 different variations of an item.

Splitting would create 5 separate listings on eBay – 5 times the listing fee but 5 times the visibility as well and WP-Lister Pro can sync the inventory status.

Flattening would list all of them as only one listing – with details about the other available variations attached as a list to the products description. Please note that Inventory sync from eBay to WooCommerce is not possible for flattened variations.

Why can’t WP-Lister Pro sync the inventory for flattened variations?

WooCommerce stores an individual stock level quantity for each single variation – so if you have a variable product with 12 variations, there are 12 individual quantities involved. While WP-Lister can merge these variations into a single eBay listing – and just use the sum of all individual quantities as total quantity – it can not “un-merge” it the other way round. When a flattened variation is sold on eBay, WP-Lister Pro has no way to decide which of the 12 different stock levels it should reduce.

That’s why flattened variations should only be used if you don’t require your WooCommerce stock levels to be updated automatically when an item is sold on eBay. WP-Lister Pro can only sync the inventory on eBay when the product is sold in WooCommerce.