• More iTunes news, reviews, videos and tour dates
• Buy iTunes music from Amazon
• • iTunes news RSS Feed

Apple's iTunes music download site has officially become the biggest music retailer in the US.

A new study by retail tracker firm NPD found that, if 12 song downloads are considered the equal of one physical CD album, the site has overtaken previous market-leader Wal-Mart in terms of music sales.

Over 50 million people have downloaded music from iTunes since its 2001 launch, reports BBC News, with over 4 billion songs sold so far.

iTunes' shift into the top spot, which the website has been able to maintain since, came during January and February, when iTunes gift cards, popular Christmas gifts, were being cashed in.

Visit NME Video for the latest music videos and artist interviews

• Previous: Procol Harum royalties ruling overturned
• Next: Simon Pegg announces 'Hot Fuzz' follow-up