This New York Times piece does its best to explain what happened yesterday:
At first, Amazon appeared to be the low-price player when it extended its $9 price tag to three hardcover books that were officially released Nov. 3. Amazon had originally offered that price in response to price-cutting by Wal-Mart on its Web site for preorders of 10 titles that included the three that were released Tuesday: “Ford County” by John Grisham, “The Lacuna” by Barbara Kingsolver and “Kindred in Death” by J. D. Robb. As of Tuesday morning, Amazon still had those titles priced at $9 while Wal-Mart, which had offered them on pre-order at $8.98, and Target, which had offered pre-orders for $8.99, had raised their prices. At Walmart.com, for example, “Ford County” was selling for $12, while “The Lacuna” was $13.50. At Target.com, “The Lacuna” was on sale for $18.89 and “Kindred in Death” was $17. But by late morning, Amazon had raised its prices — “The Lacuna” and “Kindred in Death,” for example, were offered for $13.50 — while Walmart.com had cut them again.I think the three wheeler-dealers are right on the brink of ticking off some of the customers they're so busy trying to attract. When book prices start going up and down like Wall Street stock certificates there are going to be some who feel they have been cheated by buying in when they did. They are going to experience buyer's remorse and wish they had bought two hours earlier or one hour later. And they are going to blame Walmart, Target and Amazon.
This is getting strange but I suppose they Big Three are loving the publicity so much that stranger decisions may yet be coming.