backed up with some statistics about the impact of Bitcointalk signature campaigns.
As far as I know, most signature compaign managers don't have access to this data. The few campaigns I've managed ended quickly because they didn't deliver enough new users.
I'll send a PM to Baryom and ask him about this, he's the owner of Bitsler. They have their own referral link in every signature, so they should have these stats available.
No idea if he'd be willing to share this, but it's worth a try.