|MadSci Network: Computer Science|
Unfortunately, there is no real way to predict accurately the relationship between number of users on a website and available bandwidth for download, since there are so many different connection speeds available. The only true conclusion you'll likely find is that more users means less available bandwidth, which means that everyone's download slows down. However, this generally isn't the case when several dialup modem users connect to one high-speed web server. Since modems have very little bandwidth compared to a high speed connection, several modems can connect to such a server and feel no loss of speed whatsoever.
Try the links in the MadSci Library for more information on Computer Science.