I use Haskell in production, and when choosing a library I wonder, "Is
this package production-ready?". In addition to evaluating the quality
of the code, I consider various factors such as the most recent upload
date, number of downloads, the age of the last commit, the author's
reputation, the number of packages which depend on that package, and the
number of issues open and closed.
I think it would be interesting to add a feature to Hackage and/or
Stackage which allows companies to advertise that they use a package
in production. If they elect to be anonymous, only the count would
increase. I believe that this data would not only help inform my library
choices, but also help communicate Haskell's merits to industry.