Well, just like they have the time to sit around and post 500 posts in a short period of time, I have people working for me who can sit there and count the valid threads they've started. The goal of the contest was so that people could have an incentive to post useful things. I don't care if half of their threads are in the Shoot the Shit forum, I just want to see that they've made an effort in contributing USEFUL content to the forum itself, you know, content for everyone else who is not on the clock to get to 500.
It doesn't matter anyhow, there are 10 slots to fill, and there will always be contests running, so never a dull day I guess. You don't win in this one, I'm sure you'll win in another one.