SKUs are a critical part of being able to centralize and sync up your multichannel listings. On eBay it's possible to create listings with SKU values, but also easy to change them!
To add SKUs to your eBay catalog in bulk follow the steps below:
In eBay, go to My eBay and scroll down to find Seller Tools on the left
Select File Management Center
Click Create Download Request on the right to download this view.
Once downloaded, you can assign SKUs to your eBay products by entering them in the Custom Label column
Once this is complete, you can go to the eBay exchange site and upload the file
Now, if you have the same SKUs in Zentail you can sync your multichannel listings to the appropriate eBay listing!