I suppose this one might qualify as an internet meme, but I'm not sure.
I recently have begun seeing people use the word "this" as a single word sentence, such as in response to someone else's post. It seems like it might be a way of expressing agreement, but I am struck by how awkward it seems to me.
Unfortunately it's hard to search for anything about it, since it is such a common word.
What exactly does it mean, and where does it come from?