I think this thread is the perfect example why paid per post won't work large scale.  If you look at it there are 4 pages of not a whole lot.  Sure some from each side.

But does this thread bring knowledge that others will benefit from?  Not really.  Should it be locked at this point instead of going on and on? Chances are yes.

But that is just my opinion.  I still think it's better with smaller campaigns then full forum paid per post.