New York Times Best Sellers rankings reflect sales records as reported by vendors, such as independent book retailers, book store chains, multimedia retailers, universities and multiple other sources. Rankings on each Best Sellers report reflects the sales from the week ending two weeks prior to that issue.
Best Seller lists are broken down into different categories, such as Hardcover Fiction or Young Adults. There are a number of other factors related to print books that are taken into consideration when compiling the Best Seller lists. For example, required classroom reading, textbooks and journals are not included. The appearance of a book on the Best Seller list means the book has satisfied the industry standard of universal identification.
Added in early 2015 is the combination of print book sales and e-book sales to the New York Times Best Seller list. As the e-book industry emerged, the reporting of e-book sales was not considered to be reliable enough to be included in the Best Sellers list. With the help of Royalty Share, an accounting firm for multiple major publishers, the New York Times has been able to incorporate e-books into their Best Sellers lists.
Book sales are confidentially reported from each vendor to the New York Times, at which point the Best Seller Lists are compiled by the News Surveys and Election Analysis Department of The New York Times.