Well generally, what I would do is if you want to attract people is.
-Have one of your own games (Offering other peoples games helps, when they don't have anyway to host)
-Have other products, texture packs, sprites, models, sound fx, music, they are all good, good sound fx and music is good, simply because less people do that.
-Tutorials, they attract people. But they need to be good enough.
Otherwise if you don't have anything valuable to offer, people will say, why go to another forum for help and advice and socialising when I can stay here and get all of that and a much larger society so I get more of it.