Actually quite an interesting survey. Among other things, it asks you to think about who you know in different professions.
For the purposes of this survey "know" meant "would recognize and be able to talk to them on the street".
To look just at my answers, it'd appear (of the professions listed, which was a small sampling) I know people in fairly few professions, all of whom I met offline. What it made me realize, however, was that I hardly know any professions of the people I only know online! So I may well know a cook or a hairdresser or a real estate agent or a scientist - I just don't *know* that I know them.
It also makes me ponder how I "meet" people online, at least the ones that I go on to be meatspace friends with. Generally it will be at a party, the inevitable mention of LJ will be made, and someone with whom I've been chatting will turn out to be someone who I've seen comment on friends' posts. (I later add their journal and become friends online as well as off.) The interesting thing is, does this count as meeting online or off?
Now there are quite a few people who I "know" online who I would love to get to know IRL, but they're in Atlanta or Chattanooga or Virginia or.... etc. But even of those, I know relatively few of their professions. Even those who have mentioned their careers in their blogs are not identified with them in my mind to the extent that my meatspace friends are - I never see them in their work clothes, or meet them for drinks after work, or visit them at the office. I see them exclusively through what they choose to show online.
Is this an example of the shallowness of online social networks? Or a showcase for the diversity of potential online expression? (Or, as I have inevitably found to be the case in EVERY either-or question in my life, a little bit of both...)