Fifty Shades of Grey is now the fastest selling paperback of all time.

The first novel in the trilogy sold more than 100,000 paperback copies last week alone. That's something the "Harry Potter" books and all of the "Twilight" novels could NOT do.

Experts say the success of the book has not been driven by people who regularly buy books-- but by people who buy maybe three or four books a year.

Social media may also play a part in that staggering number. How many times have you seen Facebook friends admit they can't put it down?

And the author, a woman from England who goes by the pen name "E.L. James" is now said to be worth more than 5 million dollars, thanks to a book deal and a movie contract a few months ago.  She's also been placed on Time Magazine's "100 Most Influential People in the World" List for 2012.