How these Gamasutra blogs work?

I've really started to get into the groove of blogging on Gamasutra.  I really like the exposure that comes from being listed among the fine folks of the Gamasutra community.

I've even been featured a few times, which is really flattering, but here's what I don't understand: What's the pattern? 

Does one of the editors sift through the posts and decide what gets featured?  Is there a script running which automatically features a post after a certain number of views?

Also, there seem to be two classes of bloggers: Members and Experts.  What distinguishes these two groups?  How does one go from member to expert?

If you have answers to either of these questions, I'd appreciate you leaving them in the comments.  Thank you!