Sellers those who have not made any purchase on fiverr perhaps don’t know about private feedback. Once you deliver your work buyer leave feedback. They provide a private feedback also to Fiverr team. A buyer may be kind enough to give you a positive feedback though your work was not satisfactory, they can leave negative feedback to Fiverr team.
This has a significant role on your gig performance.
Buyer must answer a question : How was your overall experience with this seller? They can give poor to awesome rating.
Additionally they give to text answer. What did you love about this gig? and How can the seller improve?
Try your best to deliver best work so buyer don’t hesitate to give a awesome private feedback.