One problem with having a route operate 3 or 4 times a week as the only service from an airline is that it becomes expensive to market it. The only real exception to that would be FRA, which could generate enough bookings through travel agents for people making online connections that it wouldn't need the same promotion. People are used to going to airline websites to book now, but if they don't know an airline operates a route, they don't find out it's available.
An example of this would be a friend who was travelling to watch a Sunderland match with his son last October. They flew to Edinburgh with Aer Arann and got the train down. When I asked why he hadn't flown directly to Newcastle, it seemed it was because he didn't know Jet2 operated the route.
Personally, I'd say the three priorities for Cork in the short term need to be
- Get a 5th EI airbus based in Cork. Some routes can take extra capacity (Amsterdam and Paris in particular, maybe Manchester or Birmingham if they want to take the routes over completely) and there is the possibility of picking up Warsaw and Budapest as well as maybe reconsidering Madrid now Ryanair have dropped it from Shannon.
- Get a 2nd Ryanair aircraft based at the airport. Even if it only operates the routes to Stansted, East Midlands and Prestwick that are currently operated by non-Cork-based aircraft. It would be an important signal of committment to the Cork base.
- Get CityJet in. Here we'll be cheering for a bit of success in Shannon because if CityJet perform well there, it may encourage them to look at Cork. The importance of CityJet would be that they operate aircraft that have greater reach than Aer Arann's and don't require the same route volume as Aer Lingus or Ryanair.
Obviously any other expansion is to be welcomed too, but those seem the best practical options for driving airport growth over the next few years.