Mut wrote: My forum isn't what's using up the bandwidth, buddy.
Did you even read what I wrote? When you get a dedicated server, you will typically get 400GB per month of bandwidth or some other very large figure. So you can easily host a lot of websites sucking 30GB or 40GB per month, especially if most of your websites aren't coming close to that (which most don't). But your actual server resources are limited, so this only works if none of the websites consume a lot of CPU resources and RAM.
In essence, it's luck of the draw. I've used these kinds of "no metering" webhosts or very low-cost webhosts before, and all it takes is one high-load website on the same server and your performance drops into the toilet.