"The New York Times' site just published their first best-seller list which includes ebooks. 'To give the fullest and most accurate possible snapshot of what books are being read at a given moment you have to include as many different formats as possible,' a book editor explained in November, 'and e-books have really grown, there's no question about it.' Interestingly, the rankings of the top 7 best-selling ebooks are unchanged if you also include their print sales

http://www.nytimes.com/best-sellers-books/overview.html