Treading carefully on this topic, as I don't want to be a rule breaker. >eek!< As a TA, promo codes are emailed to us weekly from NCL with an explanation of how they can be used; i.e. which cruises, which ships, in which combination with other codes, in combo with what specials that are currently running, sailing dates destinations, expiration dates, etc. Some are for groups only, but you can usually be added to an existing group. This is likely why someone commented above that the code worked once but not again, it may just have been a date or ship it didn't apply to. The system is something akin to the grocery store sale ads you see every week; then clipping a coupon and matching it to the store that has it at the best price, or waiting until Wednesday and taking it to the store that does double coupons then. There's a lot of moving pieces, but in this economy we're all penny pinching and there can be substantial savings in the codes, sales, offers especially in combination.