LGS:
You're right about the RJ seat-mile costs compared with e.g. 737s. However there's another way to look at it. A loco (or, as I've seen it referred to elsewhere, a "NMA" or New Model Airline
) will want, let's say, at least a 75% seat factor on a route. With a 150-seat aircraft operating once-daily (110000 seats), that means they need a route that has upwards of 80000 one-way passengers a year. And if it's a once-daily schedule, chances are that it'll be somewhere in the middle of the day, as the prime morning and evening hours will be used for service on prime routes that warrant higher frequency.
I'd suggest that routes much below this size, especially routes which have a high proportion of business traffic which is looking for convenient schedules, are not going to be so attractive to locos, who have better pickings elsewhere.
Compare a 48-seater operating twice daily, 6 days a week. That's about 60000 seats in a year. Assume a 60% load factor is verging on satisfactory (because yields are higher) - that's 36000 passengers/year for the route to be interesting to the RJ-operating airline. And that's with a twice-daily frequency which is attractive to business passengers, so the yields should be better.
(Incidentally Duo has used the CRJs for Birmingham-Athens, currently uses them for Birmingham-Helsinki, and is running Birmingham-Murcia charters in the summer, so it's likely not the range that precludes sunshine destinations.)
Of course a loco can offer some headline-grabbing fares and grow the price-sensitive market, but there are limits to how far it can be grown - as Ryanair is finding. Business travellers are not quite so headline-price-driven and, I would suggest, *do* want a good-value fare, but tend to look at overall value (e.g. do I have to waste an entire day because of the flight times? do I have to drive an extra hour to get to the airport? do I have to allow an extra hour in case of motorway traffic? etc.)
Where would you suggest Duo should fly to from Luton, then?
C.