During the same period the digital tracks sales increased 49 percent to 417.3 million, according to Nielsen SoundScan figures.

The research company revealed also which are the best selling albums in US. The American Idol finalist Chris Daughtry is leading the sales with his album, "Daughtry,"which has sold close to 1.7 million discs.

The second place goes to Norah Jones' "Not Too Late" and another American Idol, Carrie Underwood, ranks fifth with 1.1 million copies of her album "Some Hearts" sold.

The former No Doubt’s singer, Gwen Stefani, is leading the digital tracks sales with her single "Sweet Escape" sold close to 1.8 million units.

In fact, the record companies and digital music stores are already begun to shape their offer in order to meet the requirements of the digital music trend. Few months ago, the British record company EMI decided to sell DRM-free tracks through iTunes Store.

In May this year iTunes introduced a new feature called “Complete MyAlbum” thanks to which the music fans who purchased singles for $.99 a piece are able to get the full album they belong to at a discounted price.

For the moment, it remains to be seen if the other three major record companies will follow EMI’s example but maybe seeing the data announced by Nielsen SoundScan, they will reconsider their position.