At what route demand is it not worth making a flight?

[Atlantische Zeiler]

example:

If I have a 737-300 with 120 pax, and I want to fly a route 800 nm away, but there is only about a demand of 70-80 pax, does it make sense to make a route?

Thanks.

[[SC] - King Kong]

After some time (when your route image increased) it will. But it will only have a load factor based on the demand.
This means a lower profit so make sure there is no other unfilled demand closer than the 800NM on which you can use your plane.