I believe most don't even know the meaning of it which is the biggest problem. It would be helpful if communities with a topic would have their hashtags, same for the contests hosted in that community.
That would make it easier to find posts back. I give up on writing about it because I did it twice before and what I cannot find it's a pity but won't be read and I can't comment on it either. If the author doesn't care about promoting himself this is his/her own choice.