Deleting Amazon listings
There are two options to delete listings in WP-Lister for Amazon:
Delete from database simply removes the selected items from WP-Lister's database, but won't remove the listing from Seller Central. This option is useful if you need to re-create or re-import listings which haven't been created or imported properly at first.
Remove from Amazon will remove it from Seller Central at first and only when it has been confirmed that it has actually been removed (ie. the feed was processed successfully) it will be removed from WP-Lister as well - in the meantime, the listing status will be trashed.
Both options are available in the bulk actions drop down on Amazon » Listings.
Please note that deleting a SKU should only be done when you don't expect to sell this particular product again as it will remove the sales history and ranking for this product as well. If a product is temporarily out of stock, simply set the quantity to zero.
See What is the best way to manage items going out of stock? and Inventory Loader SKU Deletion for more details: