The scent, which was sold exclusively at Macy's for a limited time after its debut, has become so popular with fans, it's already on course to become the most sought-after celebrity perfume of the year.

Macy's president Terry Lundgren says, "Justin Bieber's Someday fragrance, propelled by Justin's incredible personal appearance at Macy's Herald Square, has resonated with our customers, and has now become the biggest celebrity fragrance launch on record."

Industry analyst Karen Grant adds, "If it sustains this momentum, it will become the number one selling fragrance of 2011. We haven't seen anything like it since Glow (by Jennifer Lopez) and Curious (by Britney Spears)."

Bieber's perfume success is great news for the charities he supports - organisations like the Make-A-Wish Foundation and Pencils of Promise will each receive a portion of the profits thanks to the teen sensation's deal with Give Back Brands, a company which allows celebrities to raise money for their favorite causes through the marketing of own-brand products.