Same route, less money?

[cedar tulip]

So for example i have a route from A to B, 2 planes fly from A and 2 planes fly from B, first time I get like lets say 100000k profit, but after that all the subsequent times I get less and less, unless a new day starts.

Any reason for this?

[sudden nebula]

If you are running multiple planes on one route, its the biggest mistake

Every route in the game has a fixed daily demand. If that is over your planes fly empty wasting time fuel and money

One route, one plane