Back when I actually worked it was in the streaming media field. I think the cost of bandwidth it's what's holding back the internet. Of course there are other reasons, but it's way up there.
For example it's possible to have good looking video on the web. It's just really expensive to host it. If you're into baseball, check out the site <www.protalkusa.com> if you want to see what I mean. I encoded the video on there about a year ago with older technology. It could look even better now.
What's this site running on now? I was always figured they had a dedicated server.