It's more like the way we did it back in college. These "Visitor Message" things are like the whiteboards we hung on our dorm room doors. So Sabrina wrote a message on your door. You walked over to her room and wrote a reply on her door. Etc. The only "high-tech" part of it is that the software knows exactly which thing you wrote that she responded to, and vice-versa, and can string them together to show a "conversation."