> Are any of the demographics correct?
Now that you mention it, only one. The Male/Female selectors are even so I count that a's "no guess" and not wrong, one is correct, and the other three are solidly wrong.
I was going to say that the guess of "Work" is reasonable as I do some fairly technical research for my own projects, but then I clicked and saw linkedin.com
as a reason for assuming I was at work. I never visit LinkedIn from an employers computer, it's my personal network and account. (And two of the web sites listed as reasons against me being at work were sites I regularly visit from my employer's computer.)
> Curious, do you visit many "non-US" sites?
No, mostly US based. I did see some non-US sites contributing to the demographic scoring: some supported my actual demographics, and other pointed you in the wrong direction.
Have you considered setting up an anonymous survey where people can report what about:profile says and compare it with their real demographics?