I think it is used more than people perhaps realise - and if you are deep into clojure - you are probably already on the bleeding edge (at least as far as mains

I think it is used more than people perhaps realise - and if you are deep into clojure - you are probably already on the bleeding edge (at least as far as mainstream programmers are - remember there are a LOT of them) - thus would tend to come up against places that use erlang or clojure (self selecting?). (FYI I like both erlang and clojure, and have used both in anger). I learned erlang before clojure - it I think the former helped me quickly pick up the latter, strangely.