http://steamproxy.net/id/enokha/inventory/#440_2_3338493984
Do you want a chance to win a Refined Metal at the start of every month? All you have to do is invite some friends! Simply:

• Click the "Invite friends" button at the top-right hand side of this screen.
  
• Invite as many friends as you can, the more you invite the better chance you have on winning.
  
• Keep inviting new friends as you make them to improve your chances of winning a key.
  
• We'll check the group history and check how many people you invite, then add you to the entrant list.
  
• Comment here how many you invited
  
• Check this page at the start of every month to see if you won a key:

EXTRA: For every 1k milestone we hit, I'll give out an additional key that month!

Don't think this is real? http://i.imgur.com/hVUukaY.png http://i.imgur.com/pLHkU9m.png

Want to get some guaranteed prizes for inviting your friends? Click here!

Click on this before complaining that you didn't get any keys.