If you report the spam in the Events forum, I can delete that because I'm the Events mod. I am unable to delete spam in Chapter Ops, Rush etc. because those aren't my forums. Believe me, if I could I would.
The forum mod plus John and the super mods (James, NinjaPoodle, PenguinTrax and SAEalumnus) get a notification when a post is reported. If you want to make sure that all the spam in all the forums gets deleted, send a PM to one of the super mods. They can delete the spam and ban the spammer at the same time.
It all depends on who gets to it first - if a super mod sees the notification first, all spam posts will be deleted and the spammer banned. If a regular mod sees it first, they can only fix their individual forum.
Mods can only do so much. The administrator is really the only one who can take preventative measures, of which there must be some because other message boards don't have this problem. But they do seem to be getting worse since all of the advertisements were added.