I've been noticing for a while I will randomly get lingots, then will have to check all of the discussions I've posted in to find who gave me them. It's a huge hassle, and a lot of the time I won't be able to find out who gave me the lingots. I think Duolingo needs to add a function where you will notified when someone gives you a lingot. For example, "??? gave you X lingots!" Like this comment or ( xD ) give me a lingot if you support this idea so the developers can see it!
I often give users lingots on my XP contest! You are in it and I do the random lingot giveaway every two days.