How do I get passengers to enter my airports?

[DeadSimple365]

People walk outside my airport, but no-one goes in it. How do I get people to enter?

[Lmallet]

The passengers walking outside are just eye-candy.  To transport people, you need to either:
-Have buildings in the station's catchement area.  You can see the catchment area by hitting the 'b' key.  Any building inside the blue catchement area will be served by the airport.
-Have passengers arrive via other mode of transportation (ie. shuttle buses, trains, even other airplanes).

Also, keep in mind that passengers (as all cargo) have destinations.  If there is no way for someone to get to their destination using your company, passengers will simply not show up.

[DeadSimple365]

Ah, thanks very much