“NUOVO GUSTO” are two of the worst words in the English language.

In the 1990s they started appearing on cans of Diet Coke. Actually, to be more precise, they started appearing on cans of imported European Diet Coke. And it was 1996.

Anyway, the point is, who wants their Diet Coke to have “Nuovo Gusto”? Not me for a start. I’m happy with my staple drink just the way it is, thank you very much.

It seems that I’m not the only one. May I remind you of the fiasco that was New Coke? In the 1980s the Coca-Cola Corporation became concerned about Pepsi. Its previously unassailable lead over this rival was melting away and the reason seemed obvious — taste.

Malcolm Gladwell provides an account, in his recent book Blink, of how Pepsi spooked its rivals with a series of television commercials in which Coke drinkers were invited to take the Pepsi Challenge. They were given a sip from two different, unidentified, glasses of cola and asked to say which they preferred. Time and again, they chose Pepsi.

Worse still, the people at Coke discovered that these commercials were not a con. When they administered the same test themselves, they got the same dismal result.

So what was Coke to do? It changed the taste of its traditional product, gave it a “Nuovo Gusto”, just as the customers seemed to want. The focus groups were clear: New Coke would be a winner.

And it was a complete disaster.

I am sure that Norman Tebbit enjoys this story. I can hear him chuckling as he describes how New Coke had to be supplemented with Classic Coke, and then withdrawn. It seems to confirm everything he has to say about stupid, shallow, focus group-obsessed modernising.

And he likes analogies from the retail world, too. Last week I heard him on the radio, in one of his frequent, idiosyncratic, attempts to win votes for the Conservative Party by attacking everybody in it. He cited Marks & Spencer’s difficulties as being very similar in cause to that of the Tories — that it had forgotten who its customers were and departed from its basic values.

He’s right, as well. The problems faced by M & S and the Conservative Party are similar in nature and origin. But the lessons Lord Tebbit draws from this are quite wrong.

I love M & S. I am an M & S core customer, one of its branch activists, part of the M & S blue-rinse brigade. If the company had a conference by the seaside, I’d go. I never, ever want my money back.

Every time I hear a story about the company’s problems I worry that it might disappear and then, if I wanted to buy clothes, I’d be forced to go shopping. In M & S you can buy a suit, shirt and shoes in ten minutes. How can it be in trouble? What’s wrong with you people?

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