If Southend markets itself correctly, then maybe it could make a killing brandishing its image as
London's regional airport.If it can get a few basic routes from aer arran into say, Dublin and Cork, then maybe airlines such as Flybe could expand if they see a positive reaction to some bigger hubs such as Manchester and Glasgow, while even smaller airlines such as Manx2 (seasonal into Ronaldsway),Blue Islands(seasonal into Guernsey/Alderney) and possibly Eastern (maybe could compete against their own services from Norwich to Aberdeen with a reduced weekly service from both)
And if they really want to use Southampton as their role models, maybe organising a series of charters skiing or niche through the likes of Inghams, Canterbury Travels and Newmarket Holidays would work nicely, finished of with a limited summer seasonal from Thomson to Palma de Mallorca/Alicante