Yahoo last week became one of the first mainstream digital music sites to sell a song without DRM (digital rights management) copy protection.

The Jessica Simpson song, 'A Public Affair', released by Sony BMG Music Entertainment's Epic Records label, is an MP3 file and costs $1.99 (about £1.10) to download. Because it doesn't carry DRM protection, buyers can burn the song onto CD as many times as they want and play it on virtually any portable music player.

Writing on Yahoo's music blog last Wednesday, Ian Rogers, a director of product management at Yahoo, said the firm has been trying to convince record labels to sell DRM-free music for a while. "Our position is simple: DRM doesn't add any value for the artist, label (who are selling DRM-free music every day – the compact disc), or consumer; the only people it adds value to are the technology companies who are interested in locking consumers to a particular technology platform," he wrote.

In addition, it's expensive for companies that sell digital music to implement and support DRM, he said.

DRM-free music inherently has more value then protected songs because users are free to do what they like with a file after they buy it, he said. However, the relatively steep price of the Jessica Simpson song – twice the typical cost of a song – isn't only because it is DRM-free. Yahoo is also allowing customers to 'customise' the song by choosing a specific name from a list of available choices, and that's the primary reason for the price premium, he said.

Rogers didn't say whether Yahoo had plans to offer other DRM-free songs.