Welcome to WebmasterWorld Guest from 184.108.40.206
PR does not mean much. To get a PR 6 site, all you need is 1 link from a PR7 page. You can still be getting no traffic at all.
my guess about the joke:
the joke is that Alexa ratings are based on what sites people visit who use their toolbar. meaning that if you have their toolbar installed, and you visit your site a lot, your Alexa rank will be higher. just a friendly joke. :)
That is pretty funny. If my ranking in Google was based on how often I checked where my site was in the SEPRS I'd be #1 for sure.