The trilogy has sold 30 million copies in the United States and more than 40 million worldwide.

The first book spent 20 consecutive weeks at No. 1 on USA Today's bestseller list, a record since the list began in 1993. It was bumped off last week by "No Easy Day," a first-person account of the killing of Osama bin Laden.

The books are still Nos. 2, 3 and 4 on the list.

In Britain, the three books had outsold the seven-book "Harry Potter" series on Amazon by January 2012.

It's not over yet: Universal snapped up the film rights. Rumor has it Ryan Gosling is a favorite to play Christian Grey, but if it's true, he's playing it coy, saying, "What is this book that everyone is talking about? It seems very popular."