I know the answer to this question will vary wildly, but I am going to ask it anyways. :D

Is there any type of industry average of support personnel to customers? I am working on a biz plan for a company that will initially offer shared hosting on linux systems with a control panel as well as some dedicated server offerings.

Assuming the servers are stable and avaliable (uptime measured 100+ days on average or more) and the network is fast and responsive and there is adaquate documentation for many of the services (ie setting up email, email clients, minimum info on mysql/php/etc (getting started, links to resources, etc..)) -- what might be a good figure to use for calculating the number of support personnel needed?

Are numbers such as 1000 or 2000 customers per support person reasonable? I am assuming a support person that focuses exclusively on customer support (not server support, sercurity issues, network configuraiton, etc..) via an online help desk.

Thanks for any ideas or suggestions.