You should post any codes you have here, I imagine the HN userbase is more likely than most to be interested in trying a project like that out (or maybe it's just me :))
That's an incorrect assumption. I've given out codes before. It didn't generate more content, because people quickly lose interest.
The grass is not greener on the other side. It's a dead party. Inviting a few more people isn't going to help. If they open up the gates to everyone, that's a different story, but they're not nearly ready to do that.