For the marketer, as it is for the human being, your greatest strength is always your greatest weakness.

Qantas is the quintessential Australian airline – more than an airline, in fact. It has become a national icon; like Uluru, the Sydney Opera House and the Sydney Harbour Bridge.

Becoming bigger than just the product or service you offer is a marketer’s wet dream.

My North Country English mother has called vacuum cleaners a “Hoover” all her life, and many Americans refer to a “Kleenex” when they want a tissue. That’s successful branding, and then some.

And Qantas has spent decades and many, many billions of dollars assiduously creating and strengthening its position as the Australian airline; a flying piece of the wide brown land, if you like.

Moreover, they and their ad agencies have succeeded, probably beyond their wildest dreams.

They have been tenacious, sticking to the slightly maudlin execution of “I still call Australia Home” sung by the Australian Children’s Choir despite much pressure to update and evolve their image.

Sensibly, while the ads would never win any creative awards, they knew they were on a good thing and so they stuck to it.

Perhaps now they are beginning to regret the textbook brilliance of their brand building.

With an assumption of the mantle of Australian icon comes much responsibility (when will the captains of industry accept that nothing comes without a price?), as well as many benefits.

Trouble is, once the benefits become a little less lucrative, the responsibility remains.

Chief executive Alan Joyce and Qantas management are in very real danger of undoing many decades of good marketing work terrifyingly quickly.

Fundamentally, they are businesspeople and their eye is fixed on the bottom line.

This is their job, of course, and because Australians really do love Qantas (I know we complain about it, but in the same way we complain about our Mum), we all want the airline to survive.

Nobody wants to see another Ansett, not least because it would be a real blow to our national pride.

But the airline must remain fundamentally Australian if it is to retain its place in our affections and so its market leader position.

Recently, my husband and I flew to Wellington on Qantas and realised very quickly that it was a Qantas flight in name only.

There were no Aussie accents among the staff and some of the accents over the intercom were so thick none of the passengers knew what was being said.

Oddly, this pseudo-Qantas made me feel slightly unsafe and I don’t usually feel unsettled on airlines from other countries. I think it was because I had bought one thing but been sold another, and when we feel deceived we lose confidence.

No doubt, financial realities may dictate that some routes are outsourced to other organisations, but Qantas needs to understand that the ripple effect of this can be wide, unpredictable and have serious, long-term impact on the brand.

My advice would be to be absolutely open and honest about what you are doing and why you are doing it. We will not forgive you if you try to pull the wool.

The latest ad blitz – like the recent press wrap-around telling us Qantas still calls Australia home – is a waste of money if all the editorial and comment inside the paper says exactly the opposite.

Perhaps Qantas should restrict its marketing to things like the Edna Everage campaign for discounted business class fares, which reinforces the airline’s Aussie icon status without spelling it out. It is always better in advertising terms to show us who you are, rather than just tell us.

It is a good move to have Alan Joyce out there talking about the airline and the choices he has had to make.

Keep us informed, especially about the bad news. We will forgive you for sacking 1,000 workers in hard times; we won’t forgive you for hiring cheaper, off-shore replacements in good times.

We will forgive you for cutting uneconomical routes, but we won’t forgive you for shortcuts in safety. Look at Tiger and weep.

The bad news for Qantas is that if they want to retain the advantages of being an Aussie icon, of having risen above the status of mere airline to national institution, they may have to accept a bigger financial hit for longer than they might like.

Over the long haul, however, this short-term pain will not compare with the financial hit they might suffer if they undo their decades of brand building.

Don’t do a Murdoch, Qantas. Don’t be an Aussie in name only. Not only will we see through a merely cosmetic association with Australia, we will probably never forgive you for it.

This is the price you must now pay to hang on to your success.