I can't sign up on this forum as I get an sql message about flagged user.
I also agree with tanduy about inviting friends or others you know on the internet but try to start threads that others can join on when inviting friends to join (many times threads can seem personal if its close friends)
Making the forum look a little bit more active your self will also help.
I always say that a good admin needs to make the effort and post content regardless of how many members they have....this will make the forum look busy, the best way to do this is to add an imaginary user or two by signing up again your self as a different name and (I know it sounds mad) having a conversation with yourself under different names,this will get people thinking the forum is active and encourage others to join in.
To someone viewing in from the outside a forum that does not seem to have active members is a turn off, after all would you sign up to a forum that looks as if nothing is happening ?
I will try again to join up and post there but I need to see you posting regular to encourage me to keep visiting and posting,I say this because in the past I have helped many other struggling admins by making a huge amount of posts to their forums and they just sat back and never even replied to what I had posted.
Paul