Can you request to be upgraded to business class for free?
Do they ever do it?
If you get there early and you are well dressed and there are seats available, they just might. At least have a sports jacket on.
I got upgraded to the Golden DL membership level after I posted my 50th thread to reach 600. It took several years to get to that status. It's great to have access to the entire DL archive.
I DEMAND it, Bitch!
I always book economy, but, when checking in, ask for the free business class upgrade. If their business class is not already fully-booked, it always works. A few times, they had unfilled first class seats, so they just put me there. This happened on one of my last trips to Australia; it was a god-send!