A bestseller is a book that sells enough copies to rank highly on a particular bestseller list, such as that published weekly by the New York Times.
There is no precise figure of book sales that qualifies for placement on a list. The amount needed is much higher in October, when more books are sold, then in January. One New York Times bestselling author, Tess Gerritsen, provided the following estimate:[1]
The royalties to an author on a book also vary widely. A rough range for royalties is $1–2 on a $20 book. But in practice royalties can average less to the extent discounting is necessary to sell the books.