Best selling authors

And now, the answers you've been waiting for:

Excluding Shakespeare, who was the best selling author of all time?
Answer: Agatha Christie, whose 85 books sold between 2 billion and 4 billion copies, which is actually about the same as Shakespeare despite the slightly more compressed sales window.

Who was the best selling author in the English language?
The same two: Shakespeare and Christie, followed by Dame Mary Barbara Hamilton Cartland, another Brit, whose books sold between 500 million and 1 billion copies.

The fourth best selling author of all time is also the answer to the next question:
Who was the best selling American author?
Harold Robbins, with an estimated 750 million copies.

Who is the best selling living author?
Another American — Danielle Steel, whose actual name is Danielle Fernande Dominique Schuelein-Stell, with 580 million copies sold and going strong.

Who is the best selling children's author?
If you guessed J.K.Rowling, you might be right. Or not. She is the best-selling living children's author with an estimated 400 million copies sold. But the 60 books of Theodor Suess Geisel, or Dr. Suess, have sold as many as 500 million copies. Geisel, by the way, also edited humor magazines, wrote humor articles for leading magazines and drew editorial cartoons during World War II.

Precise numbers of books sold are not public information, and book publishers are notoriously protective of those numbers. These rankings are based on a compilation from Wikipedia, which used estimates from multiple sources.