How are album sales calculated?

in this video we look at the history of album sales and how they are calculated for the billboard 200 albums chart Fair use. Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use. No copyright infringement intended.