D,
Notwithstanding your excellent summary of comparative unit cost economics, yield is always the critical factor in determining contributions to the bottom line.
Australia currently has more competition in the domestic market than ever before. A great bulk of the passengers have been conditioned to 'self serve' via the internet to save cost and the by-product seems to have been the erosion of any 'brand loyalty' in favour of the cheapest fare on the day.
DJ to an extent have been an architect of this process and the introduction of 'Velocity', in part seems to have been an attempt to recapture the leakage of itinerant passengers. The success of 'Velocity' in this regard is questionable, however, as many VFR passenger will travel 'to and from' with different carriers if they offer an apparently cheaper fare.
The comparatively high unit costs (against the Dash 8 and Saab) in markets such as Port Macquarie and Albury have resulted in DJ's competitors consistently denying them any yield from the E-Jet passengers thus far carried. Qantaslink's decision to operate the Q400 into Albury may further exacerbate DJ's losses on that sector if the schedule runs in parallel with the E-Jet.
Finally, by going to an expensive and smaller airframe for operations on trunk routes services, even for off-peak, DJ will deny itself any opportunity to make a profit form the extra 50 odd seats on the 737 that are no longer available. Their competitors, however, will be able to offer these seats (to those itinerant customers only faithful to price) as they are continuing to operate 150 seat+ aircraft.
This entire discussion may become irrelevant if the DJ share price continues to lose value at the current astonishing rate, which by next week could result in the company being worth...........?