This is pretty cool, but I do have one question:

How do you account for the fact that many of your users may not be familiar with the salary ranges in a specific area?

I understand the goal is to get a large amount of estimates for each user, to compensate for that, but my guess is that locations where larger amounts of users are located would have far better estimates. I just saw a couple of Vancouver (where I live) people, in positions I have trained and hired people in, but the estimated salary seems to be quite off considering that Vancouver salaries are noticeably lower than San Fran in reality.

Edit: It seems most of the profiles for me are Vancouver/Toronto/Ottawa, so I'm guessing that's their way of getting locals to estimate salaries.