Technology: iTunes is 10 years old today. Was it the best idea Apple ever had?

Steve Jobs put a new slide up on the huge screen. "We started about a year and a half ago to create a music store," the Apple chief executive told the audience. "That meant we have to go and negotiate with the big five music companies.

Now, before we did this I was reminded of a quote from Hunter S Thompson about the music industry."He looked up at the screen. In giant letters it read: "The music business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs."

Jobs read it out and then paused to let the slide's final line appear: "There's also a negative side." Laughter from the audience. "So I didn't know what to expect," Jobs added.

It was 28 April 2003, and Jobs was taking Apple into entirely new territory. Its iPod music player was just 18 months old, but after years of developing hardware and software, the company was now getting into services: specifically, selling music. It was a huge gamble, but one Jobs believed in.

Fast forward 10 years, and the iTunes music store has become – for Apple at least – a money trench of imposing proportions, generating $4.1bn (£2.6bn) of revenue in the most recent quarter, which keeps it comfortably the largest music retailer in the world.

It has more than 435m registered users (making it one of the world's five largest holders of credit card details) and people keep buying songs at a steady pace.The numbers are jaw-dropping: more than 25bn songs sold, 35m songs in the catalogue, available in 119 countries, and more than 200m people using its iTunes Match service, which lets them store their music library on Apple's servers

And what would keep the buyers of those putative iPhones loyal to Apple? Probably the apps – and any music services that were offered, whether streaming or stored. That April day in 2003 might turn out to be the thing that keeps Apple thriving for at least another 10 years.