A stock keeping unit, commonly know as a "SKU" is a unique identifier that helps you to track your inventory, and report on your sales.
Some sites allow you to have the same SKU on every product if you wish, whilst some sites force you to have unique SKUs on a per item and variant basis.
On Zibbet, SKUs are optional, but when used we force you to make them unique. Being a multi-channel platform, that allows you to sell on many different sales channels, we must "future proof" your inventory, so that it can be sold on any sales channel regardless of how strict they are when it comes to the uniqueness of SKUs.
If you see this on your Notifications page (the one with the bell icon on the left-hand navigation), then we've detected that one of your products doesn't have a unique SKU, and therefore you must update it before it will import successfully into Zibbet.
Simply click the "Change SKU" button and you'll be taken over to your Etsy listing where you can update your SKU. Once you've saved your changes on Etsy, Zibbet will detect the change and automatically import the product into your Zibbet Admin.