To me, "This." is stronger than "Yes.", "Exactly.", etc. In my opinion, "This." means that you not only agree with the previous comments, but you could have ma

To me, "This." is stronger than "Yes.", "Exactly.", etc. In my opinion, "This." means that you not only agree with the previous comments, but you could have made it yourself. It has a connotation of "This is the full answer", "This is it, you don't even need to read further below", "This is exactly the same thing I would have said". I might be making the connotations up, though, it's not like there is a dictionary covering this kind of things.