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 :))
> diversify the user base to generate more content
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.