When I was a child you could identify the best-selling books by looking at a display in your local book store. In America there was also the option of checking the list in the New York Times. Today it is the Amazon best seller lists which give the best indication of a book’s popularity but the top ones aren’t necessarily those which have sold the most.
If volumes of historical sales were used to determine ranking, The Bible, the Quran, Harry Potter, and the Lord of the Rings would dominate for years. Amazon offset this by using a formula that gives heavier weighting to recent sales. This allows classics such as The Great Gatsby to stand in the top 50 alongside new releases. They don’t reveal the exact calculations, and nor do they state the volume sold.
Looking at today’s top 50 in all categories I was surprised by some of the titles, and the lack of fiction, but encouraged to see that many of them are also bestsellers in the New York Times.