Amazon.com's Kindle DX e-reader mobile device appears to have sold out completely during its first few days of release. Within three days of its June 10 release, the Kindle DX was listed as out of stock on the Amazon.com Website, which now says the device will be available again on June 17.

The grayscale e-readers have proven a boon for Amazon.com's balance sheet. Although CEO Jeff Bezos has refused to reveal exact sales figures for the Kindle line, analysts expect the device to earn the online retailer billions in coming years; Doug Anmuth of Barclays Capital estimated that the device would earn up to $1.2 billion in sales in 2010 and $3.7 billion in 2012.

Amazon.com's largest-screen e-reader, the Kindle DX, was launched on May 6 in a presentation at the Michael Schimmel Center for the Arts, built on the site of the 19th century headquarters of the New York Times. In addition to a 290,000-volume library of e-books, the Kindle also offers access to downloadable newspapers and content from five textbook publishers.

The Kindle DX retails for $489 and features a 9.7-inch grayscale screen, roughly two-and-a-half times larger than that of the Kindle 2, the device's previous iteration. In addition to the larger screen, the Kindle DX includes 3G wireless access, 3.3GB of storage, active PDF support and an auto-rotate feature that shifts the page when the device is tipped on its side.

However, other innovations such as a color screen are still years off; during a shareholders' meeting on May 28, Bezos said the color displays that Amazon.com is researching are not ready for use.

Given the demonstrable popularity of e-readers, other companies have entered the market. In March, soon after the release of the Kindle 2, Sony and Google announced that Google's public-domain e-books would be available through Sony's PRS-700 Reader, which was reduced in price to $350, compared with the $359 Kindle 2.

The release of the Kindle 2 was accompanied by a good deal of media attention, with Bezos bringing horror author Stephen King to the stage of the Morgan Library & Museum in order to read a novella especially crafted for the device.

The increased interest in e-readers has also led to moves among parts manufacturers; on June 1, Prime View International, which supplies e-paper display modules, announced the $215 million acquisition of E Ink, which makes electronic paper display materials.