They provide details about Nielsen and Amazon Kindle lists of best sellers. What titles are in common? Here are the top books from BOTH lists. Bear in mind that these lists include children's, YA, and adult books.
The Fault in our Stars
The Book Thief
Looking for Alaska
The New York Times separated the books for younger readers from their adult lists some time ago during the time when J K Rowling was dominating the lists. I love that these lists do not make that separation. It makes it much easier to see which books are selling the most copies.