Demographic Data (or not)
Microsoft has a page that offers to estimate the demographic breakdown of a page's audience. (Thanks, Lilia Efimova!)
Microsoft thinks my audience skews mildly female (52%) and wildly young (25% of my readers, it thinks, are teenagers and 45% are under 25). By comparison, Efimova's readers are more female (64%) and somewhat older (only 35% are under 25). Guy Kawasaki has a 50:50 gender split, and like me most of his readers are young.
Of course, you can put up any numbers you please here. No links to the methodology in sight. Small sample sizes can say the darndest things.