I know I'm not in a position to give you any suggestions on this but how about punishing the offenders so they learn from their mistakes, there are far more individual willing to give in their best for the successful of the project. An extra amount of post isn't much of a deal irrespective of you not been paid for them.
PS: No personal attacks please lets keep the conversation professional.
There really aren't that many people willing to give their best though. Each campaign(the 1s that I manage) only has so many open spots per rank. No matter who is in the spot in most cases, users are only willing to post enough to get paid. They are not posting because they like a topic, they are not posting because they want to inform others about a subject in most cases, they are posting to be paid. If they're being paid for 20 posts, then they do 20 posts. Every now and then I get a guy who is paid for 20-25 posts per week and they do 40-50 posts a week.
Look at suchmoons small sample
Effect of Signature Bans. Even though it's a small sample size, it is a correct view of what happens when users are banned from wearing signatures. Users just fade away into nothing in most cases.
I'm not against users making money obviously, and I would love for everyone to make more money. Users need to stop thinking only about themselves though. When they join campaigns, their first thought isn't how can I help this company. Their first thought isn't to log in to the website and check out the platform. All they are thinking is please accept me so i can make some money.
I'm not trying to personally attack you, my answers in most cases are directed towards everyone but you are the one who posted the topic and the 1 I am responding to. Everyone has an opinion and I feel they should be free to post their opinion, whether I agree or not.