The Sydney-Melbourne route is where the next big airline war will be fought.
For a rival dismissed as Bleak City, Melbourne exerts a strong pull on Sydney, and vice versa, and here's the magic number that proves it: 7 million. That's the number of people flying between the cities every year, and it is equal to one-third of the population and a figure that makes it the fifth-busiest air route on the planet.
No two cities in Europe come close, nor any in the US. Only routes in Japan, South Korea and Brazil beat Australia's competing capitals on the aviation ladder, and that tells the real story of just how interdependent they have become.
The tourism trade accounts for some of it, but the real story is about money. This is the air route that channels the hustle and bustle of business, the corridor that has turned aeroplanes into flying buses for corporate commuters.
''There are people who commute every day,'' the editor of the Australian Business Traveller website, David Flynn, says. ''I catch a train to work; you might catch a bus to work; there are people who fly to work.''
For those travellers, the constant hopping between cities is often annoying but essential to the way they do business. For the airlines that ferry them it is a goldmine, the backbone of the industry. Between them, Qantas, Virgin Australia, Jetstar and Tiger Airways offer about 200,000 seats a week between the cities.
''It's massively [important], and to the country as well, when you think about it,'' the chief executive of Qantas Domestic, Lyell Strambi, said. ''[It's] huge, really, when you think about the size of our population. It just shows you the spread of business between Melbourne and Sydney.''
Virgin Australia, which last year ditched its budget-carrier heritage to compete with Qantas for the corporate dollar and has trebled its capacity on the route in the past decade, concurs.
''It's always been an important market for us since our low-cost days,'' a Virgin executive, Merren McArthur, says. ''But since our new strategy … we've obviously had an increased focus because the strategy is about capturing corporate travellers and capturing greater share of the corporate market, and to do that Melbourne-Sydney is key.''
Virgin's challenge is bearing fruit, due in no small part to the damage done to Qantas by last year's industrial rows and the grounding of its fleet. But the Flying Kangaroo remains the market leader, thanks to customers like Chris Weber, who may have grumbles about the airline but who still flies Qantas almost every trip.
The Sydneysider flies between the cities every week or two, as sales and marketing director for an IT company Infoplex. Weber said he has come to accept it as a necessary part of the job.
''I've become immune to it, I think. It's just a part of the routine,'' he says. ''The main reason is to see customers and I've also got staff in Melbourne, so I'm doing one-on-one reviews.''
Weber's commuting habits illustrate the reason for the huge numbers on those aircraft: business travellers say they often cannot do without face-to-face contact. And they're willing to put up with the stress that goes with it: predawn airport trips, taxi queues, and the times when they fly back and forth on the same day.
Another regular flyer, Matt McInnes, puts it this way. ''From a personal point of view I'd have to say it's as close to purgatory as I can find. It is the most horrible thing that I have to do on a regular basis.''
The airlines know many people hate it, and Virgin is joining Qantas in offering a raft of perks aimed at taking the hassle out of the travel grind. ''Absolutely critical,'' says Virgin's McArthur of the little extras for business travellers.
A Melbourne businesswoman Rita-Marie Hopfner, who has flown the route regularly since she founded her skincare business La Clinica 17 years ago, says she takes advantage of every perk she can to make the trip easier.
''I don't have to think about the logistics of the trip. I know I can get to the airport, drop the car off. … If I've got luggage I can check it in at valet parking and if I don't have luggage I can grab my boarding pass up in the Qantas lounge.'' The airline's premium service, she says, ''facilitates what I do during the day … Now I can even drop off my dry cleaning at the valet parking if I want to.''
Virgin has also introduced valet parking and express check-in services. It is a strategy to tempt travellers like Weber, who has criticisms of Qantas. ''Every second trip has a reasonable delay, 20 minutes to half an hour,'' he says. ''Some are excusable and some aren't. I don't really find their reasons or excuses in line with delivering a high level of customer service … They've improved a little in the past six months but nowhere near where they were five or six years ago.''
But it is the perks that keep business travellers there. ''My view is that a lot of people travel on Qantas because of the Qantas clubs and the lounge facilities,'' Weber says.
He has flown with Virgin several times as a leisure traveller, and was impressed enough that he is happy to take a look at their new business services.
Those are not comforting words for a troubled Qantas, but Strambi insists the airline will keep its insurgent rival at bay. ''They're definitely coming after us but they've got a lot of ground to make up and we shouldn't overstate their success so far.
''We're going to defend our turf very aggressively.''