But if there were ever airlines such as ryanair moving to CWL, the market would move with them ...
It might be tempting for an airline such as Ryanair to use CWL if its air passenger tax regime was far more favourable than neighbouring English airports, but to say the market would move with it is not necessarily the case. Part of the market probably would but how much?
Bristol, which by common consent, seems to be Cardiff's main rival has a larger core catchment and, importantly, a bigger local business base and more well-off leisure travellers with the means and will to travel.
If, say, Ryanair moved all its flight across the Severn to Cardiff it would need to be certain it could attract enough punters to give it at least as good a return as it gets at Bristol. Latest CAA stats (albeit from 2008) show that just under 13% of BRS's passengers begin or end their journey in South Wales.
Let's assume with reasonable confidence that Ryanair has a broadly similar proportion of 'Welsh' passengers out of Bristol. This means that around 87% of the passengers begin or end their journeys somewhere other than Wales - the CAA stats suggest that nearly 48% start/finish in Greater Bristol and 36% in the wider south west with smaller numbers from the Thames Valley, Home Counties and Midlands. Because of its smaller core catchment CWL would have to attract a much larger proportion of passengers (both percentage-wise and in real terms) from outside South Wales to maintain parity with the current Bristol set-up.
So it might not just be a more favourable tax regime that airlines would have to consider tempting though that may be. That said, the Bristol Airport management is clearly concerned.