Tip: Just from reading messageboards, I've learned that you MUST GET EVERYTHING IN WRITING! Don't just accept that some special little perk will be given to you because someone SAYS it. It must be clearly spelled out on paper. Also, & I learned this the hard way - most agencies and the cruiselines require that in order to get something like a free cabin thrown in, many times everyone MUST book within a 30 day window! (Free cabin is usually given for every so many cabins booked, but this can vary according to the price level of the cabins and number of people in them, etc. It can vary a bit by agency but there are some generally accepted standards on this.) And sometimes you may want to just divide the price of the free cabin up and deduct it from everyone's cabin so everyone shares in this perk (or the person who does all the work sometimes gets it.) And the person posting above is right: your price might be LESS if you book separately! Check it out both ways.
Last yr. we went on the Explorer in March. About l0 or ll mos. in advance we booked 2 cabins and our neighbors booked 2. We were taking some high school seniors along w/our our own kids. We used a popular agency we all see advertised on the internet and got good prices. I told the T/A that there very well could end up being as many as l0 cabins because I knew of others that were becoming interested in going. In the end, there were 27 cruisers who booked, and all contacted this agency and said they were part of our group. However, these parents and kids signed on at various times throughout the ensuing months, right up to January or February. Even before that some of the parents were asking if there had been any perks given, saying "we" should get some. I contacted our T/A, who indicated that we should have all booked within 30 days of each other in order to have qualified for any perks. He also pointed out that our price was different - meaning "better" - than what they charge groups, which was odd because he orig. told me we were getting a "group price"! I learned from RCCL that we were set up as a group and had been turned over to their group coordinator. I figured perhaps RCCL would do something for us. They, in turn, referred us back to the agency, saying it was their responsibility. Agency said it was RCCL's! I even said, "Well, how about just a free bottle of wine or something for the cabins w/parents in them?" Agency would always say, "We'll see what we can do." Which resulted in their finally saying "nothing". One of the late bookers told me she would book w/someone else because she didn't feel this was fair. I told her to save herself the trouble and just book w/the same agency as it wasn't worth the aggravation, but she felt it was the principal of the thing and the agency lost a cabin booking for 3, as well as good will, which they no doubt would have had for giving out one bottle of wine to the 6 cabins with parents in them! So, live and learn. And be ready for some work ahead! Good luck!