The Crown and Anchor Society is Royal Caribbean's loyalty program. Once you have sailed on your first cruise, you can join the society (no fee). The first level of membersip is Gold membership (1-5 cruises). At that level you are given a Gold member value coupon booklet which offers a variety of discounts and savings certificates on board, complimentary wine tasting, invitation to the welcome back party and a commemorative gift; Platinum (after 5th cruise) includes all the Gold benefits with an additon of a private departure lounge, exclusive onboard event, robes for use onboard and priority check-in, complimentary custom-air and special rates on balcony and suites; Diamond status (after 10th cruise) offers all of the first sets of benefits with the additon of priority waitlisting on sold-out shore excursions/spa services; priority tender tickets and priority departure from ship; concierge service and a concierge lounge on their newer ships; priority reservations for dinner reservations and dining asignments.
There are also member cruises (special pricing) and a Crown and Anchor magazine that is sent quarterly and has numerous discount coupons for a variety of cruises. It is definitely worth the few minutes it takes to complete the registration form onboard your first cruise!
They have just added a new level of membership Diamond Plus for those who have sailed over 25 times on RC. I am diligently working on achieving that status.