I highly doubt they think they know all the good people. It's just a much better idea to hire someone you or someone you know and respect have had a good work experience with. Hiring someone off the street opens you up to a lot of unknown, most specifically if they're a good culture/team fit.

So you think you know all the people who are "a good culture/team fit", and they aren't even particularly good. And then you complain about how hard it is to hire people? Of course its hard to hire people if you limit yourself to the thirty you know.

Hiring people you don't know opens you up to opportunities to expand your horizons and go in new directions. If a good culture fit means people you already know then you are incredibly narrow minded about culture.

I find it ironic you're accusing either me or the author of narrow-mindedness but your responses clearly indicate you haven't comprehended either of our points.

I do agree that you or your (extended) network don't know all the people worth knowing as there are always gems in random pool of people, but I think the odds are a bit better, at least from my own experience, finding them through the people in your network. How it usually pans out is that you ask your network "we look someone to do X, does anyone know anyone" and they ask their network and the loop continues until a name or a lead to a name comes up.

I'm sure they have hundreds of facebook friends...