A memo went round the London Evening Standard recently instructing that the paper would in future be calmer, cleverer and cheerier. Readers, it said, don’t want to be “coshed by doom and disaster stories” on the way home. The following Monday, the paper – which had undergone a few design changes – included “West End theatre dancing its way to box office hit record” and “Turner Prize greatest hits” among its page leads, as well as a story about how you could now have brain surgery and be home in time for tea.

The same spirit is abroad, I am told, at the weekly Times Educational Supplement. Management ordered editors to draw up weekly counts of “positive” and “negative” headlines, and to redress the balance in favour of the former. Perhaps bonuses will be handed out for one front-page splash last month: “Our primaries are heaven. They provide a safe and secure haven for children in a troubled world.”

These calls for a more upbeat tone are not new. About 30 years ago, Prince Charles called for more good news, and the Sunday Times responded with a satirical page of positive stories. About 10 years ago, I wrote education features for the Evening Standard; I was banned from writing on Mondays because the then editor, Max Hastings, believed readers needed to be cheered up at the beginning of the working week, and no education story could possibly do that. (It didn’t occur to me to offer “Our primaries are heaven”.) Later, when I edited the Independent on Sunday, David Montgomery, then chief executive of the Mirror Group (the paper’s joint owner at the time) and an opera nut, demanded that the opera critic, instead of droning on about mediocre productions, should highlight the glamour and excitement of the occasions.

Is it true that readers want cheerier newspapers? This view emerges from the focus groups so beloved of managements, where readers also say they want smaller, more manageable papers. It has been shown repeatedly, however, that the more pages and sections a paper can add, the more copies it will sell. Similarly, any editor knows disaster sells and the bigger the disaster, the bigger the sale. Nobody buys a paper to learn how many aircraft took off and landed safely the previous day. The Daily Mail, the most successful British daily paper of the age, is also the gloomiest, dwelling on rising crime, plunging school standards, imminently falling house prices, cancer threats and a country rapidly going to the dogs.

But whatever readers want, newspapers face relentless pressure for more good news from one particular source. Most advertisers do not like to be associated with bad news. If readers feel worried and insecure, advertisers believe, they are less likely to go out and spend. Guilt-inducing copy about poverty, disease, starvation and climate change is worst of all. Nor do advertisers care much for controversy. Opinions that make people angry, they fear, will spill over into negativity about products and services advertised alongside them.

This explains why free newspapers, with few exceptions, are so bland. They give a generally upbeat view of the world and rarely offer more than banal opinions. Being wholly dependent on advertising revenue, they have to adopt the cheery world view of your average corporate marketing executive. And as free newspapers grow and competition for advertising intensifies, paid-for newspapers face the same pressures. The challenge from two London evening frees – one also within the Associated Newspapers stable – largely explains the Standard’s nervousness about appearing downbeat.

Many critics of newspapers believe journalists are instructed to distort their reports or suppress certain stories in order to keep advertisers sweet. This is not true. In most papers, only the most senior editorial executives have any contact with advertising staff, who often don’t read the paper they work for. Advertisers will rarely comment on a particular article, still less complain. There is no conspiracy, no direct censorship. But every newspaper works to a formula, balancing light and shade, positive and negative, bland and controversial, to create an overall tone and a brand image. That image must attract both readers and advertisers. As free or cheap content grows, the latter become the more important influence.

That is the danger for the press of the future, and for the health of democracy. In the new digital world, it is said, information will flow freely, and so will comment. Even traditional and generally acceptable restrictions – on naming a victim of blackmail, for example – are becoming almost impossible to enforce. Censorship will be obsolete. But censorship in the crude sense is not the issue; it is a question of the tone and context in which news and comment are presented.

Newspapers are altering their business models in a way that will increase their dependence on advertising and other forms of corporate support. Some media analysts believe that, not many years hence, nobody will charge for news at all. Our press will no doubt then be full of relentlessly good cheer, rather like the old Soviet papers with their stories of amazingly productive factories, cheerful peasant girls and, from time to time, heaven in primary schools.