Comment by cfiggers

Without having run the whole company twice in parallel, once using Haskell and again in some other language, and without having measured both runs exactly the same way, I don't think metrics like you're interested in could possibly have sufficient context to mean anything reliable.

Obviously Mercury is successful, and obviously Haskell is how they did it. So it's essential to their success. Would it be instrumental to anyone else's anywhere else doing anything else? Can't possibly know, I don't think.