Just to add another anecdote; I had the same experience as viraptor. It was expected that you said bye if you were leaving, and the ghosting equivalent was to be online but not reply to a message. I knew a few people that used it async but most were not like that.

A few people actually took it very personally when the common behaviour started to change. At some point an "internet etiquette" document started making rounds with "if I'm online it doesn't guarantee I'll respond immediately".

That was around the good old times when we argued whether utf-8 posts are acceptable, whether top-posters deserve life sentences, and other very important things...

Same experience here. Among my MSN friends it was also common to say "brb" to pause the conversation for a short amount of time. In contrast, I've never seen that in WhatsApp conversations.

Ah, yup! I had forgotten about that. Brb and afk. It did really feel like you were being ignored if the person wasn't responding. Also, having to let people know if you were going to be gone for an extended period of time, like a week or more. Summer camp! That was the worst. This girl I was online-dating went to camp for a few months and came back with a new boyfriend, lol.