One Person; One store.
The largest book display was for Hillary Clinton's "Hard Choices." I counted 462 copies and about 24 CD audio sets.
Patrick J. Buchanans "The Greatest Comeback: How Richard Nixon Rose from Defeat to Create the New Majority" was about 50 copies.
Dr. Ben Carson's "One Nation: What We Can All Do to Save America's Future" was around 80 copies.
Edward Klein's "Blood Feud: The Clintons vs. the Obamas was about 80 copies.
Daniel Schulman's "Sons of Wichita: How the Koch Brothers Became America's Most Powerful and Private Dynasty" was about 10 copies.
This set of data is insufficient to draw a conclusion. However, more reports like this would provide enough data.
That's because they ordered 500 copies. 30 were probably shoplifted since people who like Hillary think they are entitled to everything for free. The other 8 were probably sent back to the publisher because some enterprising artist took a felt pen and drew a mustache.