up to 8000NM, it's largely possible. Though the real money is usually done below 6500NM.
The thing is, when you open a route, its image is low, and so is its load factor. On very short routes, it's not a problem, a 35% filled ATR can break even if he flies at least 3 times a day. But while a 90% filled 777 makes a lot of money it loses a lot of money when it's only 50% filled. Because costs are extreme, at those distance.
In other words, you need to lose a lot of money before earning some. Its a long-term prospect. So it is often advised to own a strong local network that makes a lot of profit before going long haul.