I just revised an item using the app and got this message: "Pay no fees when you share and sell through your personal link" then "share your link". Any final value fees of your item selling to a buyer through your personal link will be credited back to your a/c within 30 days.
It was on all my listings when revising with the app but not the full site. When you hit Share your Link, it takes you to email addresses which are stored on your device. I sent it to my daughter, will further advise when she gets home!