Hey, for those trying to show the sponsor ad in all threads, there's something you can do. Instead of pasting the code for the Forum Display Dev suggested (no disrespects of course), you can do a quick work around by pasting the code at the end of the "navbar" template.
I know it's not the right way, but it certainly works out just fine.
Take a look at my forum:
http://www.networkersdebut.com/forum
As of typing this, I only have 3 categories with the sponsor ad activated, Introduction, News and Design & Function.
Dev, you're welcome to add my forum to your demo site list.