Now, don't take this as gospel but I find the best times to log on are between 10:30pm and 2:30am at the moment. There is usually a constant flow of messages between those times. It is 2:35am in the morning at the moment and there are currently messages available. Late afternoon can be a good time as well but it is very hit or miss.
I noticed your message on the 'Adult Texting Chat' thread. Thought I would reply to you via PM instead as it is easier.
I was in the same position when I first started, the messages seemed to be few and far between. All I can say is to stick with it because the messages will pick up especially with Christmas on the horizon. AdminHub does go through quiet spells.