I guess that is why this offer stands. The rationale of upgrades is based on the vacant seats in premium otherwise why the airline will let us guys in its premium for pennies.
It is a lottery but not the type of picking up the name of lucky winner from a bowl ;) it is just about grabbing the opportunity. Good luck for your sign up.
Welcome to the upgrade wagon :), even i have crossed my fingers for my Kl-Perth-Kl in February. Are you going for a return flight as well? I have also signed up for my return flight because i don't want to go in premium and return in economy ;)
That is a pretty fast upgrade, I must say. I called their customer care and i was pretty impressed with the way explained my every query. I found their customer care as one of the most effective and customer friendly.