This is beginning to look like an ecommerce death match. As Wal-Mart, Amazon.com and Target engage in a price war over hotly anticipated hardcover books, retailer Sears is trying to get a piece of the action. Today Sears said people who buy one of the ten heavily discounted books on its own website, or at Walmart.com, Amazon.com or Target.com, can get an online credit equal to the sale price of the books, to be used toward purchases at Sears.com.

Sears said the credit can be applied to purchases of $45 or more at Sears.com. The retailer is requiring that people register at its website and send in their book receipts from the other companies. Right now Wal-Mart and Target are offering select hardcovers for $8.99 with free shipping; Amazon.com has them for $9. The books include Sarah Palin's upcoming memoir "Going Rogue," Stephen King's "Under the Dome," and "Breathless" by Dean Koontz.

Like Wal-Mart and Target, brick-and-mortar retailer Sears is looking to beef up its ecommerce business. Internet Retailer estimates Sears did $2.69 billion in online sales in 2008. Amazon, by contrast, reported more than $19 billion in revenue last year. Amazon represents a particular threat to these retailers because it has been steadily expanding its product categories to cover all kinds of merchandise.

Publishers and authors aren't happy about the aggressive discounting, fearing the low book prices will create a "sticky" price in consumers' minds that will be hard to dislodge. Some of the hardcovers are being sold 59 percent to 74 percent off their list prices.

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