It began offering nearly 400 Hachette titles for 40% off, with delivery dates as soon as this week. The sale was given prominent placement on the Walmart.com home page.
On Friday, Walmart said sales of physical books (excluding e-books) were up 70% since Tuesday.
Barnes and Noble's website is also offering discounts for Hachette books.
The CEO of Hachette Book Group, Michael Pietsch, wrote to the company's authors that the dispute with Amazon presents a "challenging period" but said the signs from other retailers are "extremely encouraging."
Amazon has been through this before -- and lost. In 2010, it gave in to publisher Macmillan, which wanted to raise by $2 to $14.99 the e-book price of best-sellers.
"We will have to capitulate and accept Macmillan's terms because Macmillan has a monopoly over their own titles, and we will want to offer them to you even at prices we believe are needlessly high for e-books," Amazon told customers at the time.
-- CNN Senior Media Correspondent Brian Stelter contributed to this report