Actually, I shouldn't have used the word steam b/c it in fact isn't truly streaming. It downloads scenes in chunks as the movie plays. So the cpu usage isn't an issue.
It may be ok on our server b/c we have plenty of resouces, but I'm a bit worried. I figured that in theory, because what I need is flat out bandwidth (tny bit of storage) for downloading, nothing else, there could be companies/datacenters that provide the service of low cost bandwidth for file transfer.
I could put the files I'm downloading on a really low cost celeron server with a good bandwidth for the buck, but that may be more than I need.
My big concern is less about the total transfer over the month, and more about handling a wave of visitors.
If it gets good press at the launch, or if it gets a good link from a big site, there could be a wave of people all downloading a 50MB file, and that could kill us, right? That's why the idea of having the files on a big server that can withstand that kind of burst is reassuring.
On the other hand, i can't imagine more than 20 people viewing it on average throughout a typical month, so that's a total of, what, 1 GB a day of downloading.
You could probably work something out with someone who has a dedicated server on a burstable port with unused bandwidth. I know many people (including me) have extra bandwidth now that the new craze is 1TB/server and would be willing to host your file on a per download basis.