Correction: Merry Christmas has sold 15 million copies worldwide & is the best selling Christmas album of ALL time. Also, All I Want For Christmas Is You has sold 14 million singles worldwide. Making it the 3rd best selling single by a female artist of all time. The song was written/produced by Mariah Carey & Walter Afanasieff (whom MC gave writers credits too). - BYE Samantha with yo WEAK shade. The REAL shade is that Mariah's X-Mas song will outlast ALL of YOUR favs entire career. Her X-Mas classic will be played 20-30 years from now. And, will soon snatch the title from Nippy as the best selling female single of all time. Cheers DAhhhhling! Let the FESTIVE season begin!