On Friday, Amazon began offering discounts that have never before been seen even on its own site. The move is supposedly a response to Overstock.com’s full frontal assault, which consists of discounting books to match or beat Amazon’s prices.

Dan Brown’s Inferno is now available on Amazon at a a 61% discount. And the Mountains Echoed by Khaled Hosseini has a 58% discount. Sheryl Sandberg’s Lean In is at a 64% discount. A whopping 64% discount is offered on The Fault in Our Stars by John Green.

There are signs, however, that even Amazon is not invincible in this battle. J.K. Rowling’s The Cuckoo’s Calling, written under the pseudonym Robert Galbraith, is discounted only 42%. That’s right in the usual discounting area of 40% to 50 percent. Amazon likely doesn’t want to discount something that is selling well regardless of price, and wants to keep the profits involved in that title.

Overstock.com’s shot across the bow of the mighty frigate Amazon is a long-overdue attempt to take some of the wind out of Amazon’s sails. The recent verdict against Apple has already spurred Amazon toward discounting books to eliminate the real competition that is left: the thousands of indie booksellers who together hold more clout among readers than any website ever will.

Unfortunately indies do not yet hold any kind of combined economic clout with publishers and so cannot discount books at the same rate. Thank goodness someone has noticed what’s going on in book publishing and has thrown the economic might of their company onto the battlefield.