On the face of it, the paragraph you refer to seems fairly positive for Stansted. The trouble is it's full of assumptions. What seems to be implied is that increasing numbers of passengers do not increase the wear and tear on the terminal and infrastructure (a "largely fixed cost business"). It's the old mass tourism problem revisited. Will the profit level from increased traffic meet the expenses of infrastructure maintenance and refurbishment?. There's also the assumption ("benefit of retail sales") that Ryanair passengers have the same financial power as those flying with other carriers and so will have the shopkeepers' delighted. Has that been proven elsewhere? My own suspicion is that retail margins will be lower because those products proving popular will in fact be lower margin products while higher margin products will eventually disappear from the shops. To me it seems like an exercise in chasing passenger numbers at every cost.