Last seen online...

[Gashnaw]

I am just curious, when i scroll over usernames sometime i can see when they were last online and sometime i cannot. I usually do not mind but when searching for a new role play partner, (Either to just fill my time or because another partner dropped) It is nice to know when they were last online. I can then make an assumption if my Message is worth sending (I am not going to send a message to someone who was last seen two weeks ago. But if the last person was seen an hour or so ago, I will probably send them a message.

I just want to know why some people i can see and others i cannot.