Why is "Living History" 40% off at Amazon?

[jafap]

First of all, I am a little bit torqued. Hillary was signing her book in KC today and I missed it. The TV news last night said nothing about it, and someone was hogging the paper at the library.
So I went to Amazon.com to find out who publishes it, so maybe I can drive 200 miles and catch her at her next stop. The publisher might have information on her tour schedule.

Amazon did not tell me the publisher's name, but I did notice that they are selling it at 40% off. Why? If you ask, why not? I had my own bookstore for seven years, and my wholesale price was generally 40% off from Ingram books. If I ordered 5 copies I got 41% off, and for ten copies I got 42% off. A case was supposed to be 48% off, but I never ordered that many copies of anything. I also bought direct from Random House for 44% off. Doubtless Amazon gets better deals than I did, but there is not alot of profit at 40% off - they are almost wholesaling it.

It is like they are deliberately cutting the price in order to boost sales, or do they do that for all of their best sellers?