The longer the runway at Southampton, the more pointless it becomes as it puts it in direct conflict with Heathrow. The height at which aircraft can approach Southampton is even restricted as a result of its unfortunate geography. In most countries a one hour drive up the road is considered acceptable drive time to a local airport. Heathrow is Southampton's de facto local airport. The City of Southampton itself must benefit from the proximity of Heathrow, just look at the cruise port and the accessibility from London and how it is thriving. This is nor mere coincidence. As long as Heathrow remains up the road, Southampton will be capped. Southampton's sweet spot is exactly as other posters have intimated - a small regional high frequency affluent type airport. Like London City, Like Belfast City. It is not a Luton or a Bristol and never will be. I would argue the airport would make more money by focusing on this strategy instead of the low cost airlines which don't pay airports anything!!