Actually, as I think, a signature campaign is not for only removing negative feedback. If so then all the (Red trusted) companies do it. First, do a Scam, then run a signature campaign all problem solved? No, it is not. So You have to prove that you are legit now and all the previous problems were solved. Suppose follow on
betnomy .They had some negative feedback from the beginning, Later they do some effort to prove them legit. But they have still 1-2 neg feedback but they earned some positive feedback too. (Maybe yahoo know more than us about betnomy, so better to ask him and start your journey to prove you are legit now)
You can also notice
bestchange efforts to remove their negative feedbacks.
My suggestions:
1. Create a thread and ask bitcointalk users to post anything wrong about duckdice. so that you can solve the issues. ( you can also launch a review campaign)
2. Solve all the issues, and refer them (who gave you red trust) to the thread to see recent review about duckdice. Also you can request them to review their feedback. (but don't ask them to give you a positive feedback instead of negative one
)
3. Start marketing in bitcointalk with your full power.
I hope in this way you could be helped you to prove you are legit and also Any DT members can counter the previous neg feedbacks If you can prove you legit. Good Luck