so to say, the the higher our rank in this forum the better signature campaign gained?
each signature campaign provider had different minimum requirements to their membership?
It's not the better signature campaign gained but the better payment gained from signature campaigns. Yes, the higher your rank, the payment is also high. But it will take a long time to do this.
Yes, every campaign has rules to follow and requirements to full fill. The most common one is be a constructive poster with recent posts or just be active.