The only problem with the calculation above is that it assumes a full section (which is 18, not 20), and that everyone tips at least the minimum (which per servers, doesn't happen). The "normal" seating is one 8 top, one 6 top, and one 4 top per serving team; 18 guests per seating. Yes, there are LOTS of variations based on guest requests, etc.
This info is a few years old, but it came from a trusted CM. Those in serving positions get $50 (not sure if that's per month or per check), room and board, "costumes," and health insurance while on the ship. They can extend the insurance for a very reasonable amount between contracts. In addition, they receive their transportation "all the way home" at the end of a contract as well as to begin the next contract. My server was very impressed that he was literally transported to his front door as it was far more costly than just the airfare to the nearest big city. They have to provide black shoes, off duty clothing, toiletries, personal laundry, and their initial transportation to Florida after hiring. Since the ship is not registered in the US and they are not US citizens, they are not subject to US withholding, wage and tax laws, etc. There is nothing held back for taxes; if their country collects taxes, that is their responsibility. They get a check every 2 weeks for their minimal salary and those tips which were charged. Yes, it can be a lot of money, especially for those who pay no taxes in their home countries, but it's also a lot of work. Many are supporting families back home. One CM told me that they actually collect about 3/4 of what they'd get if everyone tipped the recommended amount. Another said that it's not uncommon to have at least one table per sailing totally stiff them. However, as he pointed out, he was still getting 8 times as much as he could hope to earn at home, and he had no living expenses.
This applies only to "tipped" positions. People in non-tipped positions are paid an appropriate salary as well as room and board. Benefits are somewhat dependent on position; there is a way that officers can have family sail with them either in their living space or in guest cabins. Non-officers also get benefits of guests sailing at no charge in some situations.
Positive comments "buy" all sorts of things--4 hours extra shore leave, a "good" schedule on the next cruise (yes, they feel some schedules are better than others), notation in their employment record which influences promotions, etc. The same thing happens when a guest requests a server or assistant; a certain number of requests = extra shore time. I know this because a CM thanked me for requesting him and explained that he got time off while in port because of it! Bad comments (repeatedly) will result in a contract not being renewed.
There is a HUGE "promote from within" program. We see people who we initially met in low positions (one assistant server, one stateroom host) who are now high ranking officers! Granted, that didn't happen overnight, but it happened. There is an official training program--an assistant server can apply to the program and be trained to be a server. It involves OTJ training, but also a written test, etc. The move to head server is HUGE as it involves a lot of safety and allergy issues. Essentially every CM we've talked to has confirmed that if you want to work hard and do a good job, you can go far in
DCL. Many are encouraging their friends to apply now as with the new ships, there is a large hiring/training program in effect.