For camp counselors the growth is merit-based. If one works hard and goes after tough positions that may not be the most fun (albeit necessary), the effort is noticed and rewarded fairly in the form of more responsibility and the potential for job opportunities.

As a camp counselor we were unpaid, but I wouldn't discourage anyone from taking the position for that reason.
I feel I gained a lot of perspective, which is hard to put a value on. You get out what you put in.

Working as a camp counselor we only had a week to experience the culture, but in my short experience I found it to be pretty enjoyable. Since everyone has a common goal, it's easy to find people you get along with, though there will always be a few bad apples!