The results are in: 2/3 of respondants got their last job via referrals, which supports my confirmation bias. Not quite 20% through job boards, which is a bit higher than I'd guessed, and only slightly more than cold contacts.

Now I'm wondering whether there's any way to make a job board act more like a human network. I don't think it's 2000 people applying for a single position via a web form, to be processed by machine learning.