Let me process that... so they are going to continue to pay for (what seem to be mainly meaningless garbage) posts on their own forum and then pay, on top of that, for a signature advertizing themselves to the people they're already paying to post?
Maybe they will no longer pay for each post but then I doubt anyone would post there if they're not getting paid so basically only the signature spammers would remain. Perhaps this is some sort of play for Google rankings or whatever.