Gold and platinum records are dramatically more prevalent in today’s music industry than in the early days of rock and roll. Bill Haley and His Comets would have been given only one gold record for Rock Around The Clock. Later on it became the norm to give each of the band members a copy. Therefore, this record is an especially rare and significant piece of music history.
Shortly after Bill Haley and His Comets received their gold record for sales of 1,000,000 copies of Rock Around the Clock, the RIAA began to issue gold and platinum records. RIAA Gold Records are awarded for sales of 500,000 copies.
• More from RIAA: Link
• Wikipedia entry on Gold Records and sales thresholds: Link