You should really read the linked article with an email from the founder, age 17. This kid has built a pretty impressive site, although I wouldn't really call it a business yet. He does host it on 7 servers and uses 7 gigabits of bandwidth to handle all of the video streams. The code optimizations he must have done to handle this are pretty impressive:

http://bits.blogs.nytimes.com/2010/02/13/chatroulettes-found...