Simple, it is the same as MONEY for you to spend on-board the ship. Everything on the ship is paid with your key card, and at the end of the cruise this amount is charged to a credit card that you give them before you board. So instead of starting your account at $0 you have money to spend. Is it worth it? YES!
Yep Dollar for DollarSo it's dollar for dollar?
Yes, dollar for dollar. You can use it for any on-board expenditures. These include gratuities, alcohol, smoothies, excursions booked through the ship, and items purchased in the gift shops.So it's dollar for dollar?
Some credits are refundable, meaning if you don't use them you can get the money from Disney. Usually credits from travel agents fall in this category.
OBC can be used for DCL excursions, booze, souvies, hyper-expensive teas, booze, more booze, booze.
You are correct in that credits from Travel Agents are refundable. However, if you don't use them, you don't get the cash. They are refunded to the original form of payment -- which would be the Travel Agent's credit card. So make sure you use all the credit you are given.
I don't understand this comment; my travel agent's credit card is never tied to my booking. (And if your bookings aren't showing up on your credit card statements, you should RUN, not walk, to a new travel agent.) A passenger may get a refund to the card on file for the account (his or her own), but one should also be able to get cash on the last night.