Please don't worry too much about post counts. It's not the amount of posts that impressive, its the quality. I know I probably sound like a broken record on this topic but it still seems to not sink in with everyone. As for the lack of users on at night it is because not everyone is in the pacific timezone and most people are going to sleep.
But I would just like to stress again, post counts are meaningless when you goal is to post for the sake of posting. The goal should be to add as much as you can to the discussion with each post and try to answers others questions in a thorough manner. 99% of the time, if there is a one or two word post like "awesome!" or "I agree", its going to get deleted.
And remember, If Alex feels that someone is posting and creating spam, that user will be disqualified from being able to receive posting incentives.