I have a suggestion for you to protect sellers from people who behave to rank down sellers.
- Give a time boundary for buyers if they are giving negative feedback. That is a buyer should be old at least 1 month in Fiverr, if he want to leave a negative feedback. So that creating new account and leave negative feedback for sellers will be reduced.
- Many of buyers don’t know about the process how gig works, and sometimes what they are ordering. So giving this time boundary can teach them about the process here. They will learn it by time.
- Limit buyers for placing orders continuously just from one seller, if that person already has left a negative review for that seller. If a buyer got to place many orders from a unique seller first, and if wait few days and then started to leave negative feedback using those orders, it can stop by automatically. Since a program can detect it.
- Use these kind of buyers’ PayPal IDs to limit them. Store those IDs in a special(pending black list) column and eventually move those IDs to a black list according to the statistics of his and related seller. So that they can’t use that PayPal ID to place more orders from that related seller.
I know these are very difficult things to do. But I mentioned what I got from experience here.