According to market researcher NPD Group, Apple’s iTunes has become the number two music retailer in the U.S. behind Wal-Mart. The ranking is based on sales numbers for 2007. NPD analyst Russ Crupnick said that there has been “almost 50% growth in digital downloading in the past year (2007).” The group claims that about 10% of music acquired in the U.S. was through legal downloads for last year and that the customer base of digital downloads grew by 5 million for a total of 29 million. NPD also points out that the amount of music purchased in the U.S. rose by 6% in 2007, but due to the decline in CD sales and the increase in digital download sales music spending is down 10%.