Depends a lot on the position.
F&B positions are usually based on tips, unless you are management.
Hospitality such as reception used to make 400USD a week and work 10 hours a day.
Embarkation day is always more work.
Celebrity and Royal have a wide variety of hospitality positions that pay more, if you speak other languages there´s an "International Ambassador" > 1900,00USD a month.
Onboard Marketing desk pays commission on cruises sold onboard.
The shops are nice, I did shops for a long time
www.hardingbros.co.uk
and
www.starboardcruise.com/
they are concessions which run the shops on most ships,
both companies have Celebrity ships but Starboard has more.
Hardings pays 160pounds a week + commission
Starboard 500USD a month + commission
I like Hardings much more.
Good thing about working the shops is that you usually dont work while the ship is on port, having free days.
I loved working on ships, but with the dollar low as it is its not as good as it once was.
Hardings do phone interviews.
Crew positions such as dinning room, cabin, deck etc, work a minimum of 10 hours a day and have one afternoon off a week.
Some 7 years ago there was a class action against Royal and they were the first who started to regulate such matters.
But in other lines you are really on call 24/7.
Thats for Crew positions.
Staff positions have a lot easier.
Staff are Reception, Shore-ex, Casino, Spa, Shops, Photos...
Dont trust employment agencies online.
Go directly to the source, Hardings, Starboard, Royal, Carnival etc.
9 in 10 agencies are schemes.