Something I've noticed a lot of is that some airports will have demand for very long flights, but not enough demand to justify a large aircraft. Some regional jets have pretty impressive range, but it just seems idiotic to fly a 75 seat airplane 2000 miles. Are these low demand long haul routes profitable at all in the game? Or is flying a regional jet half way across the world as crazy as it sounds?
It depends. Usually, those lines are barely profitable. And there is a limit beyond which ful consuption increase a lot. For the A148, you can still make some small money on a 1800NM route, but at the extreme limit of 2150NM, you're pretty sure to lose money, whatever your pricing.Even below the reasonable limit, those flights cannot be the core of your strategy. They can be at best placeholders : in 2008, I set up a A148B, on 2 daily 1700NM routes with 70/80 demand, and the place breaks even, when you count staff & marketing costs. In 2024, demand has increased to 120/130, and I'm putting a MAX7 that makes OK money. I said OK, I didn't say big bucks. When you carefully micromanage prices, you should end up in the green. Not by much, but still better than letting money sleep.
What is completely crazy is flying with tech stops. I toyed with ERJ145XR between London City and a tech stop in Newfoundland, or SW3 from Nice to Bobo Dioulasso with a tech stop in the Algerian desert, and this is a complete waste of money. Whatever the price, whatever the seating configuration. But it's fun.