Well,
even if i was still online I don't answer every message before I leave the site.
It is the nature of the beast.
First I need to notice that my pm indicator is flashing.
Sometimes we don't.
People like SD and Gizmo probably get more messages than most and can't keep up.
That is why I opt for email notification for a reminder
Then even if I do read it, it does not mean I need to respond at that very moment.
Even though you can see that I had viewed it.
Maybe I don't have a answer at that very moment and I need to research it.
Or I just don't have time to answer right now.
Or maybe they just ignore you.
I have longtime buddies here that may not reply for a few days or not at all because they forget.
Hard to keep up with multiple PM's a day.
Also just because they show online does not mean they are viewing the site.
I leave this site open in my browser on occasion while I am sleeping.