case in point, we (http://minecraftforum.net & http://minecraftwiki.net) have 60m page views per month (as Stackoverflow does -- according to Joel) and we're nowhere near the top 500 according to QC.
I checked, the graphs you linked are visits. As of today our visits is at just shy of 11,000,000.
Edit: Ah, you're right. I see, under "visitors". Yeah, that looks about right, we have closer to 3m uniques. So many different terms in stats :D I wonder what the value of uniques vs. page views is.