Often I think the hello is actually a way to bait you into revealing that you are available. Sometimes the request that is about to come is something the reques

Often I think the hello is actually a way to bait you into revealing that you are available. Sometimes the request that is about to come is something the requester knows you are likely to either ignore or at least putting off responding until later; the hello is innocuous enough that if you reply, then it has been established that you are present and so ignoring subsequent messages becomes a bigger challenge.