More than 10,000 copies were sold on its first day of publication with some bookstores sold out by lunchtime, making it the fastest selling collection of short stories. The short story, set three years before Harry Potter's birth, revolves around his father James and his friend Sirius Black. "The limited edition What's Your Story? postcard collection has very nearly sold out on its first day of release, though customers should rest assured that there are still handfuls of copies left around the country," Contactmusic quoted Waterstones spokesman, as saying. "The magnitude of sales easily makes it the fastest selling short story collection since records began in 1994. There just isn't anything comparable," the source added.