Can you describe how the signature campaign would work? We have a referral system that gives you a special URL to share, so would it not be possible to put that in your signature?
it would work just like regular advertisement on bitcotalk forum, paid to signature campaign participants
participants will be paid based on number of posts made per weekly not on the usual page views/impressions
having ref system doesn't necessarily induce people to voluntarily advertise your site in their sig space,
but paid signature would definitely boost exposure (advertise) your project to whole forum readers