In January 1979, this method was abolished, and certifications were instead based on unit retail sales: sales of 60,000 were awarded silver, 100,000 for gold and 300,000 for platinum.
This method was abolished. This was in January 1979. Certifications were instead based on unit retail sales. This was in January 1979. Sales of 60,000 were awarded silver. Sales of 60,000 were awarded 100,000 for gold. Sales of 60,000 were awarded 300,000 for platinum.