I often keep a server open for extended periods to make sure I catch those who are looking to jam. However, most of the time I'm not actually playing but I'm somewhere nearby and ready to jump in when someone joins. This often leads to people joining the server and leaving shortly thereafter. First thing to note is that even if there is activity on the server, you won't hear anything until the interval cycles through once. Then if you still don't hear anyone playing, MAKE SOME NOISE! I won't know you've joined the server if I'm not at the computer but I will be within earshot and notice when someone starts playing. It's disappointing to miss out on potential jams when I see someone has joined and left. So all you need to do if you see me online is make yourself known audibly and I will likely be coming around to join in.