On January 2, Facebook founder and CEO Mark Zuckerberg announced he would be challenging himself to read a new book every other week in 2015. As part of the effort, called A Year of Books, he would invite Facebook users to read along and participate in discussion of the books, which he said would have an emphasis on “learning about different cultures, beliefs, histories, and technologies.”

The post naming the first pick, Moisés Naím’s The End of Power, generated more than 7,000 “likes.” Since then, Zuckerberg has stayed true to his resolution, but the engagement from Facebookers has slowly fallen off. As we approach the halfway point of 2015, PW tracked the response from users for each book selection, and the impact of each choice on print sales.

A Year of Books

Each new pick is announced with a post on the A Year of Books Facebook page.

Book Sales Week Before Book Sales Week After Book Sales 2nd Week
The End of Power 29 3,089 1,298
The Better Angels of Our Nature 223 475 423
Gang Leader for a Day 186 348 162
On Immunity 285 300 303
Creativity, Inc. 530 874 737
The Structure of Scientific Revolution 101 201 138
Rational Ritual 2 9 26
Dealing with China* N/A 13,118 7,716
Orwell’s Revenge** 0 0 0
The New Jim Crow 2,187 2,096 2,345
Muqaddimah*** 0 0 0
Sapiens 657 1,254 TBD

Source: Nielsen BookScan.

* Picked just prior to its release date.

** Out of print; Free Press is releasing a new edition on June 30.

*** A 14th-century text that is out of print. Free PDFs of are easily found online.