Not sure if this has been suggested before, and don't really know how to check, but the idea is simple, you would export your collection and would share it with your friends or around the internet.
I had this idea before but was too lazy to suggest it, clearly we have the same thoughts though. This would work out well, because there could finally be a way for people to say "Hey, if you want to get better at "x" (x being a skill or mod), this collection of maps i made is especially good for that."