More control over ads.

It seems that, currently, you need to select one of the "Forum" positions in order to get access to the conditions that allow you to set an ad for a specific forum - this is extremely bad design.

All of the forum-specific positions are, quite frankly, awful and I'd much rather place an ad in one of the Global positions. But if I place an ad in one of the global positions then I can't set the conditions to display the ad in a specific forum or forums. This needs to be changed.