The novel, which recently reached the top of the fiction charts, is the first of a trilogy by British author E.L. James, published by a small independent Australian press in May 2011.
The print version has been hard to come by in bookstores, so many have been forced to read the e-book edition.
"Hundreds of women write to me every day asking where they can buy grey ties," ABC News quoted Lyss Stern of Divamoms.com, who recommended the novel before it became popular as saying.
"The books are really making people want to have sex again. They're a Band-Aid for marriages that maybe weren't falling apart, but were getting stale," Stern said.
Margot Sage-El, the owner of Watchung Booksellers in Montclair, N.J., called the trilogy a "phenomena."
"It's coming in and out of here so quickly that none of us have read it," Sage-El said.
"When I got here this morning, men were lined up outside the door, saying their wives sent them to pick up the book. When there were two books left, an 86-year-old man waddled in, asked for the book and said, 'My wife sent me in, she thought it would be good for her book group,'" Sage-El said.
'Fifty Shades of Grey' is about shy college student Anastasia Steele, who interviews the successful and attractive entrepreneur Christian Grey for her campus magazine. The two begin a passionate affair that forms the basis for a tale the author's website claims "will obsess you, possess you, and stay with you forever."
James' website offers a soundtrack for each book that includes everything from opera to Frank Sinatra to Britney Spears. Why each book has a soundtrack is left for the reader to wonder.
According to The New York Times, readers aren't the only ones who have been trying to snap up this book. American publishers battled over the rights to re-release the trilogy, with Vintage Books winning the fight with a seven-figure offer.