If you're trying to find these developers through job postings I don't think you're going to have much success.
Your target market is developers passionate about Clojure so if you want to hire those you need to go to where they are; which most likely isn't Monsterboard.
Once you get to 10 it's a very different ballgame.
So why doubt this same thing can happen again? It's like doubting that MD5 will ever be broken, or questioning whether something like Roman numerals can be improved upon. Of course it can, and will.
Unfortunately the song doesn't "keep it real".
At Clojure meetups there's a palpable sense of eagerness in everyone I talk with that isn't using it on a daily basis yet though and I would find it hard to believe if that didn't have a significant monetary effect.
As far as recruitment goes, especially in large numbers, I will definitely concede that it will be hard to scale up to large numbers without using traditional hiring channels and that those channels will most certainly fail you when recruiting this specific a skill-set.
I must admit that I was looking for a bootstrapping co-founder instead and even 50% market rate didn't make sense in that context so I don't know if they would've followed through, but it sure as hell didn't feel like a tough sell.