My question is how much difference will there be between job posting here and on other niche boards. I searched in Chicago and everyone on the GitHub jobs is also on the Joel on Software's job board. Maybe the results are better for other places that have more good software jobs.
Are there too many job boards chasing the same quality listings?
It's early days; too early to compare Github to JoS. Note that we posted 2 reqs to Github but would never post to JoS; the overlap you noticed is imperfect.
(We're hiring in Chicago too, but we have no trouble reaching Chicago candidates and so didn't spend on a third posting).
Sorry, I'm writing very badly today. We didn't post an ad for Chicago, even though we're actively hiring there, because we feel like we have pretty good candidate outreach in Chicago already; that, and we wanted to see how Github job ads did.
Are there too many job boards chasing the same quality listings?