New York - In Manhattan, a queue stretched around the block at a Barnes & Noble bookshop.
In Singapore, some fans called Books Kinokuniya about two weeks ago to reserve copies.
Fans of British author E.L. James' Fifty Shades Of Grey erotic trilogy clamoured on Thursday to get the first copies of her new book, Grey, a version of the first novel told through the eyes of the male character, Christian Grey, a handsome business tycoon with a penchant for kinky sex.
Grey was the highest Kindle pre-order book of the year on Amazon.com when it was released as an e-book at midnight, on the character's birthday, and is expected to be an instant bestseller.
Publisher Vintage Books, a division of Knopf Doubleday Publishing Group, supplied a million copies of the novel to bookstores.
In New York, fans camped out overnight, arrived in trains caught at dawn and devoured the first pages on the sidewalk. High school girls, mothers with toddlers and housewives queued down Fifth Avenue to get their hands on Grey and have it signed by James at Barnes & Noble.
James, who dedicated the novel to fans who asked for a book told from Grey's perspective, said it was not difficult to write.
"I thought it would be hard but once I found his voice, it was quite easy. Like any man, he is not observant at all," she said in an interview on the Today show.
Early reviews panned the book.
The Telegraph called it "as arousing as the diary of a sex offender".
The Economist's review was headlined "I'm a creep".
In Singapore, the book got a lukewarm response. At Times Bookstores at Plaza Singapura, sales were slow, said a customer assistant. On Thursday afternoon, only five copies had been sold.
Books Kinokuniya at Ngee Ann City Takashimaya Shopping Centre reported brisk sales, however. A store assistant said: "Shelves are getting empty and we are constantly topping up."
For a Singaporean fan, Ms Vivien Quek, who read e-books of the trilogy, the hype has "died down since the movie was out". The 32-year-old said: "We know the ending, and reading Grey is just an add-on." She said she would also download the latest book.
The trilogy sold more than 125 million copies worldwide and was published in 52 languages.
The first book was turned into an R-rated film by Comcast Corp-owned Universal Pictures, starring Dakota Johnson and Jamie Dornan, which has grossed more than US$569 million (S$761 million) at the global box office. Film adaptations of the second and third books are planned.
Reuters, Agence France-Presse, Additional reporting by Chitra Kumar