How is inventory updated?
The quantity count of items is reduced by one each time an item is ordered from the system. Once the quantity count reaches zero, that item is taken off line.
If you sell an item elsewhere, you can sign into MusicStack and manualy delete the item from the system so that your inventory is accurate.
Many sellers also routinely do an Inventory Upload and select to replace their entire inventory list with a new one which also serves the same purpose of bringing their catalog up to date.