Make your server unique is my advice, if you want your server to be successful you need something that only your server has. think about it like this why would I go on your server when i can go on the other million faction servers. Make yours unique wheather it's a weird plugin no other server would ever use or custom plugins; or maybe even a unique way of doing the factions system. Anyways thats my two cents, best of luck to you.
-legomanz56
P.S.
Good staff who are active are really important too.