Archiving old threads won't really effect bandwidth anyways ... especially since most people only view threads from the last 30 days.
And bandwidth is a webmaster's nightmare. Particularly when you are running a major site. Advent Children.net uses anywhere between 200-300+ GB bandwidth a month. It's a nightmare. Our main server has an allocation of 150 GB/month, and of that we are currently using around 130 GB/month. On top of that there are media servers [well not really servers, but more so 100 MB allocations of webspace which I name media1, media2, etc] which someone has kindly donated for the site. I use these for all of the trailers I have on the site, and although they are not bandwidth monitored, they do remove our files if we are using too much. Media server 1 had all it's files removed a couple of weeks back ... what a nightmare! I had to re-upload everything onto the next media server!!!
Maybe one day someone will donate me some webspace for Oddworld-Web's media [the movies and the Oddworld Internet Explorer].
I'm sure someone is making money off bandwidth out there. And not the hosting providers. We get bandwidth allocations through our ISPs for downloads, yet site owners pay for bandwidth uploads and downloads. So someone is making double out there.
Abe Babe...