The cruise lines limit the number of comp players that can be on a sailing because it doesn't make for a good experience if you're in the casino and can't get a slot machine, all the tables are filled, and it's way too crowded. So the ship may not be sold out, but there may be no more bookings available for comp players. This is especially true for sailings that are on certificates or direct mail pieces as they tend to reach casino capacity faster. Therefore, when a good offer is available, we recommend you book it quickly!