Google analytics really is the most accurate way to tell. Most web hosts provide site stats as part of their package - but it's a pretty lame program like Webalizer that doesn't really give you all the info you need. Google analytics is free, easy to set up, and hugely helpful from an
SEO standpoint. It's always nice to know where your visitors are coming from. That's not the focus of many of the web stats programs out there, unfortunately.
(That's not to say that your package is bad or anything, Joe. You might even be using Webalizer - with more of the options available than my previous host allowed. I think it has a lot to do with the permissions on the server.)
Question for you guys though - to be a Platinum member there, do you really need to have ISDN?