Just because that population doesn't come up as "wealthy" in the stats doesn't mean they can't be more economically viable than a million bargain-hunting sun-seekers.
Pretty much sums up the last decade of rapid airport development in the UK.
Should it not be considered that an airport that relies heavily on revenue from footfall generated by one or two 'low cost' airlines is at significant risk if one of those airlines collapses/pulls out? At the other end of the spectrum there are airports who have diversified their aviation interests and have not put too much emphasis on low-cost airlines, their passenger figures look pretty dire, but are still commercially viable none the less. This is why I believe the thread is null and void.