29/11/2012 12:14 GMT | Updated 27/01/2013 10:12 GMT

'Thank you for taking the time to post your views on our wall.

This is entirely a matter for the Sun - it is not for us to comment on editorial decisions.'

So said Tesco's 'Customer Care' when a No More Page Three supporter asked why it continues to shovel advertising spend into the Sun.

To be fair, other retailers (Sainsbury's, ASDA, Morrisons, Argos and DFS), also target customers in the Sun. Alarmingly, LEGO ran a voucher promotion in the paper during half-term, boosting circulation among parents, in a drive to sell toys. Are these companies failing to understand the power of brand association?

We've seen some telling examples. After some corporate dithering, Nike withdrew sponsorship from Lance Armstrong when drug-taking evidence became overwhelming. The trustees of two charities bearing Jimmy Savile's name considered rebranding, but ultimately decided to fold. Remember how Accenture quickly dug a big fat bunker between themselves and Tiger Woods, when his personal behaviour no longer reflected brand values, and tainted their sponsorship?

Any company using celebrities risks their protégé 'going rogue' and poisoning their brand. The case of The Sun is subtly different. This organ of the Murdoch press remains unchanged. The Page Three topless girl has been on newsstands, her modesty covered with a flimsy front page, for forty years. But the culture in which it operates is changing, and its editor and major advertisers are failing to respond. A useful parallel is the Robertson's marmalade golliwog. A 'British Institution' and 'harmless fun', just like Page Three claims to be, it objectified and ridiculed black people, and was mercifully discontinued in 2001.

Recently, Marketing ran a cover feature on cultural shift. They warned managers:

'When brands lose contact with the shifting demands of their customers, they are on the road to ruin... A time comes in the life of every company when refreshing its brand position and changing its corporate culture is essential for survival.'

After the nauseating happenings in Rochdale, and Jimmy Savile's alleged decades of abuse, the public is belatedly reacting against hyper-sexualisation. The Everyday Sexism Project allows women to voice, online, the abuse, disrespect and sexual aggression they experience daily. One in three schoolgirls reports inappropriate touching at school. Girls walking and cycling in the street are grabbed by men demanding sex acts. Women at work find that even their managers make unwarranted comments about their breasts, their clothes, and their intellectual ability. Our culture still turns women into objects.

But why single out the Sun? It's simply this. The Sun, a daily newspaper, sells 2.5 million copies, and claims 7.5 million readers, every day. It peddles soft porn alongside the TV guide and the footie reports, for 40p. Page Three can't be shown on TV, but the paper is not even on the top shelf. It's a pervasive reminder that women's achievements go unreported, and only their boobs are news. Newsworks reports over a million Sun readers aged 15-24; they don't report on under 15s. Topless models do not feature at weekends, to protect children. I do wonder how children are made miraculously blind to it on weekdays.

Even worse, since Rebekah Brooks' editorship, the models have been ventriloquized. Captions used to say something like: 'Brenda, 19, from Wellingborough, works in a florist's. I know you'll agree she looks blooming marvellous'. Brooks replaced this biography-lite with the nasty 'News In Briefs' speech bubble, in which the model is made to spout Murdoch propaganda such as:

'ZOE is certain Tony Blair was right to take Britain into the war with Iraq. 'You don't need to be an international diplomat to realise the world is better off without Saddam. We should be proud of what has been achieved.'

The post-modern joke is that Zoe will never be an international diplomat, nor anything else, because, with those tits, boys, she couldn't possibly possess a brain.

This is where we learn society's views of women. If you are a woman, it is the standard by which you judge your own appearance. If you are a man, it is where you see passive women, stripped to their knickers, available as an object for random sexual gratification. And, because of its presence in workplaces and public spaces, The Sun itself is a tool of abuse. Here's evidence from the Everyday Sexism Project:

'A male colleague of mine buys the Sun every day on his lunch break. He then usually picks up Page 3 and shows it to everyone else in the room asking "would you do that?" I am then made to feel bad if I comment because apparently he's a "lovely bloke".'

'Was on the train this morning and overhead two men discussing how awful the story was about the girl shot by the Taliban for wanting education for women, over a copy of the Sun. A minute later - in front of a carriage full of men, women and children, they were leering over Page 3 and how 'stupid' the model was based on the (completely made up in reality) news in briefs.'

I don't understand why so many women appear to read The Sun. I wonder how many of us buy it. I do know from my own observations, that it is mostly women who do the weekly shop. No More Page Three, which has over 58,000 petition signatories, is advising supporters to boycott these retailers this week. Sadly, there are relatively few untainted supermarkets around. It would only take one major supermarket to break ranks and stop advertising in the Sun, to earn our gratitude; to give us a choice as to whether our hard-earned household expenditure goes to subsidise pornography.

If this were racism, anti-Semitism, or homophobia, the big advertisers would find The Sun's editorial decisions suddenly relevant. As it is, spending money with The Sun is not morally neutral. In an environment where brands are even more attractive assets than a model's breasts, advertisers could avoid guilt by association. I wonder if any of them will.