I understand that the crew members on these cruise ships do not make much money and probably get very little actual time off (though that free time is on an awesome floating resort and/or tropical island), but...should a service fee really be charged for everyone over the age of 3?
I agree a service charge should be assessed. Sure. The NCL employees work hard making other people happy while they're on vacation.
But is a 3 year old, 4 year old, 5 year old, 6 year old,etc really going to remember or appreciate that service, or even recognize that a service was done? Probably not.
I don't have kids so I don't know what the cruise staff does that goes above and beyond to earn that $12 per day, as per the cruise agreement. But I have a hard time believing it's as much work as making a 21 year old, 30 year old, 40 year old, 50 year old or 60 year old, etc just as happy.
Like I said, I could be wrong. I don't know first hand.

I might take note of this on the upcoming cruise because I am definitely curious.
Tips should definitely be given - in the recent Applebee's debacle I'm on the waitress' side - but I think the cruise corporation should re-look at their age to start charging the $12/ day or have a lesser amount for those under the age of 10.