Understanding Virgin Voyages' level upgrade/bidding system

If you're fortunate enough to be able to book a cruise with Virgin Voyages 1 , you might have seen the "bid to level up" option hidden away on your booking confirmation. The bid-to-upgrade system is weird . It's not well explained. Sometimes it is counterintuitive. Timings are vague. It's a lottery-of-sorts, and like any lottery it becomes a little easier to win if you can figure out how it works.…