Apparently, the pre-orders and first-day orders of the 9.7-inch wireless reading device, priced at $489, exhausted Amazon's supply. Amazon officials were unavailable to comment immediately.

Analyst Van Baker of Gartner Inc., said Amazon is probably intentionally keeping the DX supply low to attract more interest.

"I think it's just Amazon being Amazon, and wanting to create a little buzz around it and give the impression that it's so popular they can't keep it in stock, which keeps prices high," he said in an interview. "All that's positive if they don't overdo it." The direct through the Amazon.com Web site.

Amazon's site included some of the DX, with some concerned about the $489 price, but many were ecstatic about the larger screen.

One reviewer, N. Jenkins, "Mommy of Many Interests," said she could display many of her music books on the DX and place the device on her music stand while she played the cello.