Fashion, mediated through peer group pressure, has always played a role in children's lives. When Tom Brown arrives at Rugby, proudly wearing a cap he thinks "a very knowing affair", Harry East tells him immediately to get a hat, because "if you went into the quadrangle with that thing on, I - don't know what would happen". Matron calls East "the coolest new boy in the house" and appears to have meant then (Tom Brown's Schooldays was published in 1857 and set in the 1830s) roughly what she might mean now. Substitute "trainers" for "hat" and "shopping mall" for "quadrangle", and you might conclude that things haven't changed much.
Yet modern commerce has taken things to entirely new levels. Peer group pressure - to wear certain kinds of clothes, eat certain foods (usually high in sugar, salt and fat), possess certain toys, buy the latest technology - is now backed by highly sophisticated marketing through television, film and, above all, the internet. In the 19th century, most children were ruthlessly exploited as workers; now, in Britain and the United States at least, they are exploited, scarcely less cruelly, as consumers. Beyond about 35, most adults, particularly men, run out of buying steam; by the time you get to my age, you can hardly be arsed to get yourself new socks, let alone bother with the latest mobile gizmo.
Children, therefore, have become the motors of economic growth, responsible (through what they spend and what their parents spend on them) for a market worth nearly £100bn annually, up 33 per cent in five years. Moreover, they influence an unquantifiable proportion of adult spending on, for example, cars and holidays. If parents show children insist they spur themselves to renewed effort. Companies once sold to children by marketing to parents. Now it's the other way round, with children sometimes pointing their parents to advertisements for loans or new credit cards.
As Ed Mayo and Agnes Nairn put it, in this shocking and passionate book, the 21st-century child inhabits "a seamless, branded world". Commerce invades children's wardrobes, lunch boxes, bedrooms, and even their friendships and families. Children's entertainment, whether on film or TV, is dominated by marketing opportunities, with High School Musical or Doctor Who, say, producing endless spin-offs in the form of toys or dolls, cushions, T-shirts, towels and so on. High School Musical alone has spawned 300 different licensed products, earning Disney a hundred times what it originally spent on the film. Half the budget for Sesame Street comes from merchandising revenue.
On the internet, it gets worse. It is not just that nearly half the sites visited by children try to sell something, often in a crafty way: by, for example, providing a "wish list" to email to friends and family. It is also that some children become what the marketing people call "consumer advocates" or "brand ambassadors". They are bribed with free products or even cash to spread the word about the latest brands. Primary school girls in effect act as salespeople on commission, promoting goods such as the Barbie Girls MP3 player and getting bonuses from the marketing company Dubit if they leave endorsements on chat-room sites or send photographic evidence of themselves showing a product to enthralled friends.
Modern parents agonise over keeping their children safe and protecting them from, say, "stranger danger". But danger comes not only from streets, playgrounds and middle-aged impostors in chat rooms. As research by Mayo and Nairn proves, kids' favourite websites throw up numerous links to gambling, dating, cosmetic surgery and even soft-porn sites. They usually lack warnings either that a link is paid-for advertising or that the content might be unsuitable for under-18s. The internet's standard business model is still not widely understood, even by adults. Nobody expects to pay to get access to a website, any more than they expect to pay to enter a shop. But everybody knows a shop exists to sell something; yet it is not so clear, particularly to children, that many apparently innocent websites have the same function. On the net, little is as it seems and, almost by necessity, it is often not made explicit what is being sold.
Following the old Jesuit injunction, corporations want to get children young and brainwash them into acting as good consumers who develop lifelong brand loyalty. The net is the most effective tool yet invented for achieving this aim, allowing commerce to communicate directly with young people without parental oversight. Objections to the "nanny state" or the government playing Big Brother are redundant. Governments are amateurs when it comes to invading privacy or moulding personal behaviour. Cookies on your computer monitor every site you visit on the internet, as well as whom you exchange emails with and what you write about. Corporations can then send out "targeted" advertising, and they target children at least as much as adults.
What should be done? Mayo and Nairn propose that schools teach "financial capability"; but, as they point out themselves, children spend more than twice as much time on-screen as they do in class. Perhaps because it is so unfashionable and so contrary to the quasi-anarchist principles of the web, the authors do not call explicitly for regulation. That, however, has to be the answer. In just a few years, corporations have exploited a new medium and stolen childhood. Somehow, we have to reclaim it.