When the law-abiding viewers of BBC4 tune in to the fourth series of Mad Men next week, they will be only seven weeks behind America’s Don Draper fans. This may sound like we are pitifully behind the times, but the lag last time around was over five months, by which time anyone who’d glanced at the online entertainment and arts pages that raved about the show had had the plot thoroughly and comprehensively spoiled.

And those of us who like to watch our television shows in the same year that they were first broadcast have the pirates and illegal-downloaders to thank. The BBC has hastened to show this series of Mad Men, partly because it believes that it has lost viewers to piracy; that those who just couldn’t wait were simply breaking the law and downloading it rather than putting their hands over their eyes and ears, and ignoring the internet chatter for months on end.

The music and television industries have done their best to persuade us that pirates are only one small criminal step up from terrorists. They destroy the industries they steal from, they fund organised crime. On stark DVD warnings, they seem to be on the verge of branding us with hot irons.

But most downloaders aren’t like that at all. In June 2008, a University of Herts survey discovered that teenagers had, on average, more than 800 illegally copied songs on their MP3 players. And even if one disapproves of the young – both their musical tastes and their choice to play it out loud in its tinniest form on the bus – most of us would surely agree that they aren’t all criminals, 800 times over.

And in November 2009, an IPSOS Mori poll discovered something interesting about the lawbreakers: those who admitted illegally downloading music spent far more buying music than their clean-living counterparts - £77 per year, rather than £44. In other words, by going after those who infringed copyright with gusto, the music industry was also going after its best customers.

Once better legal alternatives for music downloading began to proliferate, piracy decreased: people were happy to stream music from Spotify or YouTube, just as they have been to buy songs from iTunes.

So when will television follow? The impetus to download TV shows is far more pressing than it is with music – if you don’t hear a song for a couple of weeks, at least no-one will review it and tell you what happens in it. And there are some signs that TV channels are realising that catering to their fans is more sensible than wishing they would behave differently.

Sky, for example, broadcast the final episode of Lost in the UK earlier this year, at the same time that it was being shown in the States, as did broadcasters in six other countries. They realised that showing it at 5am was still preferable to showing it to the very small Venn diagram overlap of Lost fans who had the patience to wait.

But the real change will come – as so often – from Apple and Amazon. On Wednesday, Steve Jobs announced the new version of Apple TV, a box small enough to fit in your hand, which will stream TV and movies straight into your home. You can rent a movie for $4.99 or an episode of, say, Glee for 99 cents. If this becomes internationally available, it should demolish the number of illegal downloaders. A core of them will remain, of course, but most of us would happily pay 80 pence or so to watch a TV show we love, knowing that the money will support the making of more programmes like it. And Amazon have already raised the stakes, offering to sell some TV shows for 99 cents an episode, rather than renting them for the same price.

Sales of DVD box-sets may be disintegrating, just like CD sales before them. But TV companies should learn from the rather cack-handed example of the music industry.They can simply charge small amounts to watch things legally, rather than criminalising their biggest fans.