A FEW years ago Universal Music Group spied a gap in the market. How about a CD for people who grew up in the 1950s and wanted to revisit the pop music of their youth? The label pulled together songs by British and American artists, some well-known (Buddy Holly, Roy Orbison), others largely forgotten. “Dreamboats and Petticoats” was released in time for Christmas 2007.

That gap turned out to contain a seam of gold. “Dreamboats and Petticoats” has sold enough copies to be certified as double platinum. It has inspired a West End musical and three follow-up albums, with another due in November. In total the series has sold 2.3m copies, mostly in Britain—a country where fewer than 120m albums were shifted last year. And virtually everybody who bought the album forked over money for a compact disc. “They don't download, and they don't want to download,” says Brian Berg of Universal.

“They” are consumers in late middle-age or beyond, who increasingly drive the music market. In Britain people aged 60 or over spent more on pop-music albums in 2009 than did teenagers or people in their 20s, according to the BPI, a trade group. Sony Music's biggest-selling album worldwide last year was “The Gift”, by Susan Boyle, a 50-year-old Scot whose appeal derives in part from her lack of youth. And what has happened to music has also happened to other forms of entertainment.

The noisy disruption of media business models by the internet in the past decade has obscured a profound demographic transformation. Whether they are buying music, listening to the radio, reading newspapers or watching television, media consumers are ageing even more quickly than the overall population. Rather than trying to reverse this trend by attracting younger people, many companies are attempting to profit from the greying of media.

Grey anatomy

In America the audiences of all four big English-language broadcast networks are looking middle-aged. Since 2003 the median age of a prime-time CBS viewer has increased by three years, according to Nielsen, a research firm. Viewers of ABC and NBC are five years older; Fox's, seven and a half. In that time the median age in America has probably risen by a year and a bit. Some shows are greying faster than the networks that carry them, in part because they have fan bases that are ageing naturally. The audience that tunes in for the desperate housewives of Wisteria Lane is approaching 50 (see chart 1).

Indeed, every network except Fox had a median age of 50 or over last year. That is significant because advertisers tend to be most interested in how a show rates among people aged between 18 and 49. As Alan Wurtzel, head of research at NBC, puts it, a growing proportion of viewers are becoming almost invisible to marketers—“forgotten but not gone”.

If broadcast television is growing old gracefully (helped by Botox injections), newspapers are racing towards senescence. Between 2002 and 2010 the proportion of American papers' regular readers who were aged 55 or more rose from 37% to 46% (see chart 2). Fully 43% of readers of Britain's Daily Telegraph and Daily Express are at least 65 years old, according to the National Readership Survey. Such papers are littered with advertisements for comfortable shoes, cruises and stairlifts.

The reason why newspaper readers are ageing so quickly is simple: the young are abandoning print faster than everyone else. They may pick up free papers to read on public transport, but when reception is good they tend to plump for mobile phones and the internet. The Pew Research Centre, an American think-tank, finds that 65% of 18- to 29-year-olds describe the internet as their primary or secondary source of news. Only 14% of people aged 65 or over say the same.

In music, too, the young have drifted to illegal file-sharing and, more recently, to free streaming services such as Spotify. By and large, the middle-aged and old have not. David Munns, who manages Bon Jovi, a rock band that was formed in the early 1980s and is still going strong, notes that older fans have more money and more scruples. They also regard illegal downloading as “too much work”, he says. Bon Jovi's “Greatest Hits” was the 15th-biggest-selling album in the world last year.

As the young cut back on conventional media, their elders consume more of it. In Spain 54.2% of people aged 55 to 64 routinely listened to the radio last year—up from 46.6% in 2000. As a result, the Spanish radio audience has greyed even as overall listening has risen. Japanese baby-boomers carry on buying music at an age by which earlier generations had largely stopped. Singers who appeal to the middle-aged and old, such as Hideaki Tokunaga and Junko Akimoto, rule the charts.

The same is true of television. British 55- to 64-year-olds spent an average of five hours and ten minutes a day watching television last year—50 minutes more than in 2001. The middle-aged and old now have free digital channels dedicated to their tastes, such as ITV3, home of wrinkly detective dramas, and the highbrow BBC Four. They have seized on easy-to-use gadgets like digital video recorders, which increase their enjoyment of television.

The young are not watching less TV. But some of their viewing is now done through computer screens. And much of it is of unconventional channels. Instead of the evening news, American 20-somethings watch “The Colbert Report”, a spoof news show. MTV has moved beyond music videos into reality shows, and is enjoying its best ratings in years. Media outfits that appeal to immigrants and their children often have youthful audiences. Univision, a Spanish-language broadcast network, boasts a median age of 37.

Now they're 64

Greying audiences are causing discomfort among media executives. But not as much discomfort as you might expect, given the industry's long preoccupation with youth. The ageing of the large baby-boom generation means there are a lot of potential customers in their 50s and 60s. Furthermore, the executives argue, people of this age are worth much more than in the past.

The practice of measuring television audiences by the number of 18- to 49-year-olds they contain is simply an historical anachronism, argues Mr Wurtzel of NBC. David Poltrack, his counterpart at CBS, agrees. It used to be assumed, he says, that older people had already worked out which brands they liked and could not be persuaded to try new things. But the middle-aged have taken to toys such as e-readers and iPads. Mr Poltrack has devised an alternative way of classifying viewers that emphasises tastes and attitudes to media (for example as “sports enthusiasts” or “surfers and streamers”) rather than age.

It is not surprising that ageing television networks should argue that the old are becoming more valuable. But the West's economic slump has given force to their claims by sapping the earning power of the young. In March the unemployment rate among Americans aged 20 to 24 was 15%. For 16- to 17-year-olds it was 29%.

Lack of work has combined with tighter lending standards to squeeze young people's buying power. Between 2007 and 2009 average spending on new cars and trucks by Americans under 25 fell by half, according to the Consumer Expenditure Survey. It fell by 31% among people aged between 25 and 34. By contrast, expenditure by those over 65 was flat, and the over-75s actually spent more, on average. The young also spent less on audio-visual equipment and services—that is, television sets and cable TV—while the old shelled out more. This helps to explain why advertising money has flooded back to the ageing broadcast networks since the recession. Advertisers are not so in thrall to the cult of youth that they are prepared to overlook such a shift.

Desperate, but not for younger viewers

Another reason why media companies are not too worried about the ageing of their audiences has to do with a change in business models. A firm that depends on advertising needs to attract valuable consumers. A firm that relies on subscriptions, by contrast, cares only whether its consumers pay their monthly bills. And perhaps the strongest trend in media in the past few years—stronger even than ageing—is the growing reliance on subscription as a means of paying for content.

BSkyB, Discovery Communications, ESPN, Netflix: many of the media industry's best-performing companies and hottest stocks of recent years rely on subscriptions. The recession may have slashed advertising and discretionary spending. But most people carried on paying the bills for entertainment. As a result, subscription-based businesses were able to sustain spending on content. So clear are the advantages of these businesses that even firms that have habitually relied on advertising are moving to copy them.

As newspaper advertising has declined, publishers have raised the prices of subscriptions and single copies. Last year 41.3% of the New York Times's newspaper revenues came from subscriptions—up from 28.8% in 2007. Similarly, broadcast networks are battling for “retransmission fees” (essentially a cut of subscriptions) from cable and satellite distributors. As the broadcasters become less dependent on advertising, sheer numbers will come to matter more than demography.

The clearest sign of this shift is the appearance of online paywalls. Last month paywalls went up around the New York Times and the Dallas Morning News. The websites of Britain's Times and News of the World began to restrict access to subscribers last year. Hulu, an American website that carries broadcast TV programmes, and Spotify, a European music-streaming service, are both pushing subscriptions.

One good reason for media firms to erect paywalls is that new media are beginning to age, too. The proportion of people aged 65-plus who get most of their news from the internet may be only 14%—but in 2006 it was a mere 2%. Online video streaming began as a young person's hobby but has increasingly become mainstream. “Often it's the young who adopt a technology, but others follow them,” explains Patricia McDonough, a television analyst at Nielsen.

With a few exceptions, media firms have found it hard to make money online. Consumers seem to tolerate fewer ads, and rates are low. When digital media were the province of youth, this did not matter much: media firms could argue that they were at least promoting their brands to young people, while deterring them from piracy. But let the middle-aged and the old, too, discover they can have entertainment for nothing? That would not do.