There was always a way to display ads in the vb
forum since day one.
In vb3 it was the inc_ads.php file which has been around as long as classifieds has been around.
In vb4 since day one it was with the vb4 plugins released. This was through a block of ads that displayed right on the forumhome.
The example I show you above is a vbulletin sidebar block the last ten ads title and description.
You of course would need to be a customer with access to be able to obtain support and mods and even the latest code for sure.