You also may want to consider the amount of time the plane is at your airport. Persuading airlines to operate fast turnaround times will enable you to get more flights in, but it might suit you to keep a plane on the ground for 30 minutes longer if that will help relieve a very busy period. Overworking your Air Traffic Control facilities could have disastrous effects. Before arranging for 3 Jumbo's to leave within a 15 minute period you should make sure that you have a large and efficient infrastructure. It's easy to keep tabs on all the Airlines who operate from your Airport.
Good design is important so that aircraft and support vehicles can keep moving.
Leave room to expand inside the terminal. Once the contracts start coming in you'll need space to place more facilities, like extra check-in desks. Cargo facilities are another source of revenue. Some Airlines will demand such facilities, and almost all will take advantage if they are provided. Usually ships the same business day.