Yep, and it's been going on for years unabated.  I have less of a problem with account sales for the purpose of earning more money in a sig campaign (though that's certainly a problem) than high-ranked, green-trusted accounts falling into scammers' hands.  And no, there's no way to stop it from happening--not on this forum and not anywhere else.

OP obviously realizes what the problem is here, but I don't like the solution he's proposed simply because it's impractical.  You'd need someone to enforce it, for one, and that isn't going to happen.  Nor would it be popular with anyone involved in sig campaigns, or even Theymos for that matter.  Lots of solutions to the spam problem have been suggested in the past few years, but Theymos hasn't put restrictions on campaigns (except for Yobit, which was a good move).  The best thing we got was the merit system, and that was huge.

I think it certainly would be a lot less if campaigns didn't exist.  Plus not all sig campaigners are spammers--it just so happens that most spammers are in sig campaigns here.  Does it even matter what the quality of the traffic is for earnings purposes?  I can't say I understand that aspect of how the forum earns money, but I'd think that traffic is traffic.