[Top100EbooksRank]

http://www.publishersweekly.com/pw/b...ong-tail-.html

Houghton Mifflin Harcourt trade president Gary Gentel said there is “no doubt” that the move to e-books is affecting the sale of backlist titles, and he provided some HMH math. At the publisher, the print book sales ratio of titles is 40% frontlist/60% backlist while for e-books it is 20/80. “What this says to me is that with the decline of physical space, which cuts into the display of mid and deep backlist, consumers are moving to e-books because of availability,” Gentel said. One reason e-book backlist is growing is that readers who finish an e-book and want to read more titles by that author can immediately download the title, publishers said.

Physical
40% front- 60% back
Ebook
20% front - 80% back