I'll see tomorrow whether or not I'm still part of the campaign. Either way, it was about time that something was done to get rid of the major part of the Bitmixer shitposters. One thing is sure, your appointment will surely makes me want to improve my post quality directly. 
What I've already been asked several times is 'how to improve posting quality'. You could attempt to contribute to the community by writing a "guide" with some pointers for this (I'm not aware that there is one). Make sure to make it self-moderated and discuss with someone else prior. <- This is an example of something that a spammer is very unlikely going to do for the forum. They are likely going to respond to the thread with "Thank you, now I impruv my posting quality.".Then let them do that. I think instead of batting this tired old mouse around, admins ought to try things--anything--out, see what works. And even though I'm in a campaign now, I would have no problem with nuking the signatures altogether. The spam here is just goddamn ridiculous, and it's painfully obvious that it's the sig campaigners' fault.
Agreed. While it may be near-impossible to completely halt account sales, adding the risk of being permanently banned (both seller and buyer) will definitely kill a huge chunk of the market.