I think this feature will greatly benefit people in learning the Clojure library.
When I solve a problem, show me the most often used primitives by solutions of other users.
For example, I solved 70. Word Sorting using sort, .toLowerCase and .split. Some of the other solutions (of users who I "follow") used .compareToIgnoreCase and sort-by. It would be really informative for 4clojure to show these primitives from other solutions even if I don't "follow" some of the other users.
I call this "social learning" as it facilitates learning of unlearned primitives from other people's solutions.
This is a cool idea, but I'm not sure how we could do it.
Might make for good blog material if you want to run analytics on a problem that has a large solution set.
I think that you could give access to all of the solutions from your back-end and anonymize them. That means obscure all of the variables and remove user id reference.