Fatcurry is 100% right on the money. More poeple make games more fun, it's like a vicious circle. If you don't have players, the game isn't fun. If the game isn't fun, you can't get players. However, once the game starts to grow, it should be the opposite effect, the game is fun therefore people want to play.
My experience with this game. I started playing in November. Bfiddy told me about it. He found out through 2-3 other people that we learned had been playing this game for a while. As soon as I joined, I forced another friend to play (then he drafted a broken player and we were all mad cuz he didn't even care) and then I got 2 more friends to join within 1-2 months. They've already started recruited other friends to this game. People who are invited to this game aren't the ones leaving, the ones leaving are the ones stumbling across this website randomly, or the ones who aren't good.
Like I've been saying all along, community fosters growth. You can form your own community with your friends whether real life friends or digital friends that only exist via cyberspace (the ones that told me about this game). And then take it upon yourself to teach the basics to people. I skype/msn/phone call/text my friends and help them learn the game as I'm leaning it form those that recruited me. The exciting thing for me and the federation I'm in is just to see us starting to excel and do really well because we're all helping/giving advice. Again, the community factor.
So basically, invite a friend, then teach them! if you don't know, ask somebody who has been playing longer! If somebody rejects you, ask somebody else. Probably not the best idea to ask somebody in your own league that is trying to beat you though ;) unless they're nice. I spent the season in d5 trying to give advice to my opponents and they didn't listen, but whatever.