Nielsen SoundScan is an information and sales tracking system created by Mike Fine and Mike Shalett that tracks sales of music and music video products for the U.S. and Canada. This information is collected by over 14,000 retail, mass merchant, on-line stores, venues, digital music services to determine the top 10. Anyone who sells music with a barcode can be included in the list.
Metallica has released 9 studio albums, 3 live albums, 2 EPs, 24 music videos, and 45 singles. That is a ton of music! The band has won 9 Grammy Awards, and has had 5 consecutive albums debut at number one on the Billboard 200.