What do youy mean with "designations"? If meant "destination", there's no fixed rule. I can tell you that the longer is the flight, the better will be your result, because you're "pulling" a/c range, which is what you paid the price for. One of my best routes with the A330 was DOH-HKG: close to range limits, good demand even if with tough competition and a good seat configuration. The a/c was making about 2,5mln with low commonality costs/because when the a/c could not operate for A-B checks, there was an A343 flying the same route. To summarise: low fuel consumption, common type, modern a/c, 7days sched, good seat configuration, more than one flight per day (in this case, 3 per day).
If you plan to use your a/c for short haul route, you've made a big mistake. I think that the only profitable route with such an a/c could be a LAX-JFK only to fill up the gaps between longer flights/empty scheds.