Due to the lack of certain allowances and payments we as crew receive, the total salary and other costs for a concierge is about the same as one extra Economy rank crew member. Apparently top brass intended the job description and functions to 'evolve' naturally, with a lot of input from the Concierges themselves. I think it could potentially turn out very well, but this lack of a firm job description may rather have been thrown in the deep end initially.
If any AKL based concierges are reading this - the minority of you who sit on a jumpseat, or stand with your arms folded while we're doing the service, constantly squeezing past carts, and loudly shoot the bolt locks on the door and turn your bunk lights on in the middle of our crew rest period - you are not appreciated. The majority, luckily, are great people who are doing their best to establish a niche for themselves and we're enjoying having an extra person onboard.
I suspect that eventually the Concierge role may evolve into assisting in BP during the meal services. This would seem to me the best way for Concierges to make themselves known and available to Business pax before they all go to sleep in their lovely bedseats. However, again, since the role has been defined so fluidly, it depends on the people themselves.