I'm not even a mod around here.  Let's call it my "idea."  

The signature campaigns would have to pay more to fewer members to run their campaigns.  This is by design to raise the barrier of entry and encourage honest participation in the forums.  The goal is to eliminate account farming and spam posts I thought, so those things need to be disincentivized.  You shouldn't need to post a ton of spam before you earn the right to advertise and your only reason for donating to a place that so many spend so much time shouldn't just be to get a good return on your investment.  I'd like to think there's a self respect element that comes along with it.

When I first came to these forums, everyone had their address in their signature.  This was because they would help someone with a problem and receive tips from users for being helpful.  It was great.  The forum was full of helpful people growing interesting ideas and quality conversation.  Now, users are incentivized to ask dumb questions and disappear or fake goods sales to their alt accounts wasting everyone else's time who responds to their threads.  Wouldn't it be better if we as a community got back to tipping people for being helpful instead of paying them to spam us?

Perhaps even a "community tipper" of some kind could be introduced, where a portion of the donations received is paid back to helpful members of the community.