I know all sorts of websites for hiring marketers, but all of them are for services related to already established businesses (SEO, PPC, social ads, etc.).
Where's a good place to find people for early-stage marketing?
To post in various places. Help you refine your target audience. To engage people on Twitter.
I have a hunch that they might not exist and that that's another of the many jobs founders have to do. But who knows, maybe there's a place.