All that does is compel the recipient to stop what they’re doing and wait until you send the message, which, if you’re typing up a wall of text, could be minutes. This is like calling someone on the phone and, when they answer, saying “hello please hold”. Don’t do it; it’s super rude.
Snow Crash is almost kinda satire, but also not. Also, I believe, the first use of the term “metaverae”. It’s a fun read.