I think you've got a few options. Route 1 is to spread it by hand, post it on 4chan /v/ or on Neogaf and ask for advice there, as you did here.
Second option is to buy actual ads on those same sites, Facebook, Twitter.
But the best option, though the hardest, is for you to begin making the game show off your personality a bit more. Make it more unique. Think Kingdom of Loathing or Candy Box: both have totally unique writing and worlds, and aren't just the standard orcs and goblins. What are you into, personally? What's some private joke you have with yourself you can spread across this game like a layer of butter?
Finally, giving people more ownership of the game world will encourage them to invite friends. Perhaps an "invite 5 friends, get your own house in the game" type thing. Growing it via social networks is half of that, but the other half is allowing players to have something in the world they'd want to show to someone else.
Good luck! You're already doing a great job. Watch player growth religiously. It's your guide to where advertising works.
Second option is to buy actual ads on those same sites, Facebook, Twitter.
But the best option, though the hardest, is for you to begin making the game show off your personality a bit more. Make it more unique. Think Kingdom of Loathing or Candy Box: both have totally unique writing and worlds, and aren't just the standard orcs and goblins. What are you into, personally? What's some private joke you have with yourself you can spread across this game like a layer of butter?
Finally, giving people more ownership of the game world will encourage them to invite friends. Perhaps an "invite 5 friends, get your own house in the game" type thing. Growing it via social networks is half of that, but the other half is allowing players to have something in the world they'd want to show to someone else.
Good luck! You're already doing a great job. Watch player growth religiously. It's your guide to where advertising works.