Hi Wwinfl91,
Not totally sure how the Upgrade Fairies work their magic. From heated discussions on this and other boards, personal experience and comments from our travel agent, I've gathered the following, and I could still be wrong:
1) Much depends on when you book, and how well the ship is filling up at the time.
A way to assess this is to monitor fares via Yahoo, Orbitz, Vacations-to-go, and the ships' own websites. If prices are dropping, you have to assume they need to drum up sales, and an emptier ship means more cabins to upgrade to. If prices are rising, then demand must be strong and you may not get anything more than what you booked.
2) We had never booked "guarantee" before, figuring they'd just stick you in the worst cabin next to the boiler room. But it was explained to us that this just means you'll get that category, or better. So the strategy would be to book a guarantee in the lowest cabin category you can live with. So that if you get an upgrade, great, if not, it's still just fine.
3) As the sailing date nears, the cruiselines have to fill up the ship. That's when they start to lower prices, so they can advertise these deals and get new bookings. But they can't afford to turn off the customers who've already booked. So they might stick new customers in lesser cabins, based on the fact that they're paying lower prices. That's when those who booked earlier and paid more, get bumped up. This may be happening more because people are getting so used to booking last minute for the best deals, the cruiselines now have to encourage people to book earlier, and upgrading early bookers is one way to reinforce this desired behaviour.
4) People who've sailed with the line before, tend to get upgraded first and more often. We noticed this on our March sailing on the Spirit. Not only did we get a price break, but got bumped up 5 decks. So what if it was Carnival...8 days cost us $385 US each.
We're told Princess treats past passengers very well. We'll find out once we get this one out of the way, and book our next!
5) A lot can happen around 70 days prior to sailing. Something about groups who've prebooked a bunch of space, having to let unsold cabins back on the market. Or else it's that around then, people have to pay in full. Not sure. But the cruiselines get a clearer picture of how the ship is filling up. I noticed, for example, our sailing has come down in price a bit in the month since we've booked. And our agent has said we may be upgraded again. She's seen people get bumped up 4 times in the months leading up to the cruise.
6) I do think this upgrading stuff happens more rarely than we'd think. And I'm sure people never get bumped up from say, an inside cabin to the Royal Suite.
7) Our upgrade could also be because we are first timers at Princess, and getting into to that demographic of frequent cruisers, and maybe they wanted to "wow" us from the start. Who knows. This is also the first time we're with this particular travel agent, and she knows we've been on three vacations in 8 months, so maybe she did something that's within agents' power parameters, and called it an upgrade.
8) So maybe bug your agent more. Check out current prices of the category you booked - if there's a huge difference, ask about it. At the very least, you'd be getting some information for the next time.
Again, I could be totally wrong about these observations. There could be, in fact, absolutely no science to this, just pure dumb luck!
Have a wonderful cruise. And if it's not too much trouble, please report back any observations you have about the basketball court, i.e, how busy it is, whether it's just kids, any organized games, etc. My husband's looking forward to shooting hoops 11 decks above sea!
Judy