The rate is too low for full/sr/hero member, it can't attract these people to join your campaign.
Ok, new rates:
For Junior: 0.00015 BTC per constructive post
For Member: 0.0003 BTC per constructive post
For Full Member: 0.0005 BTC per constructive post
For Senior Member: 0.0007 BTC per constructive post
For Hero: 0.001 BTC per constructive post