What? That's crazy. That makes it easy for interested parties (marketers, gov't agents, etc.) to hide amongst real moderators, or in other words makes it more difficult to detect the source of spurious moderation.
If it's done at random and only given to those who participate in discussion and get responses and good karma, then manipulation becomes far more difficult. Unless the marketers, government agents, or other unwanted parties are involved in the same capacity as everyone else, then you shouldn't have to worry about spurious moderation.
The only caveat to this is that it encourages a further echo chamber effect, but then again you're already engaging in one by participating in a forum anyhow.
