I want to offer potential clients as many features as I can, from a marketing perspective, but don't want to set the stage for a PR and support problem when, for example, a client buys a 10MB account and then creates 50 email accounts.

It looks like most resellers are giving roughly 10MB of monthly bandwidth for every MB of storage quota, but I haven't been able to discern any such pattern for these other services.

So... what sort of ratios and rules of thumb are experienced folks using for setting limits on email accounts, ftp accounts, subdomains, parked domains, SQL databases, etc.?

Thanks --

Bill