E-readers have been all the rage of late and for good reason: they offer the promise new streams of revenue by selling subscription content. Meanwhile, consumers are flocking to the devices as some are racking up sales in the millions.

Some of the larger publishers have sat up and taken notice and are even looking to create a digital marketplace to sell content on the devices. 

Confused? Below is a lay of the land when it comes to e-readers with all of the statistics that matter to publishers including formats and how to submit your content to each device's marketplace.
 

Current Players

Nook

Who: Barnes & Noble

Formats: EPUB, PDB, PDF, JPG, GIF, PNG, BMP, MP3

Library: Over 1,000,000, including Google Books.

Network: AT&T 3G and Wi-Fi

Sold: Unknown, though shipments are delayed until Jan 2010. Barnes and Noble claims it's because of high demand.

Difference Maker: "LendMe" feature allows users to “borrow” an e-book for 14 days keeping alive the "pass along" measurement. The Nook also features an SD memory slot so users can add larger media such as MP3's.

Publish: Barnes and Noble asks you email: ebookpublishersinquiries@book.com. Store is still in its infancy only four newspapers, nine magazine titles, so the Nook folks are likely busy.

Cost: $259

Bottom line: The Nook is still getting its feet on the ground, but with the support of a big-box book store, the device should be able to compete with Amazon's Kindle. Technologically, the devices are similar but the true difference-maker could be in the Nook's e-book store, especially if Amazon does not rethink its publisher split that currently entitles Amazon to 65 percent of e-book sales. 

Kindle

Who: Amazon

Format: Kindle (AZW), PDF, TXT, Audible, MP3, MOBI, PRC, HTML, DOC, RTF, JPEG, GIF, PNG, BMP

Library: Over 360,000 magazines, books, newspapers etc.

Network: Whispernet, powered by Sprint. Wi-Fi depends on Kindle model.

Sold: Unknown. Though analysis estimate 2.7 million units in 2010.

Difference Maker: Publishers have to use Amazon's DRM'd file format. The Kindle has the most sales among all e-readers.

Publish: Publishers can sell content with just an RSS feed, though Amazon takes 65 percent of sale. Local newspapers are $5.99/month, national and foreign papers range from $9.99 to $14.99. Magazines are $2.99 and under. Publisher program details are here.

Cost: $259

Bottom line: The Kindle is the market leader, not to be ignored. Amazon is constantly tweaking and updating its devices offering several versions of the e-reader. Pressure from Sony and the Nook should force Amazon down from its monopolistic high horse to give publishers better revenue splits. As evidenced by the recent News Corp. deal, some publishers are already jumping ship, suggesting that Sony is offering better revenue splits. Publishers should still sell content on the Kindle, but hope that the revenue splits become more favorable as more competitors arrive on the scene.
 

Sony Reader

Who: Sony

Format: DOC, PDF, RTF, TXT, BBeB, EPUB, BMP, GIF, PNG, JPEG

Library: 400,000 plus Google Books.

Network: Only Sony’s “Daily Edition” model features 3G and Wi-Fi support from AT&T.

Sold: 300,000

Difference Maker: Several versions, book-focused.

Publish: Sony's Publisher program. Unlike Amazon, Sony offers RSS feeds for free. Sony's store is mostly focused on books and does not offer any newspaper or magazine subscriptions, though the company is expected to announce partnerships sometime this month.

Cost: $199 - $399

Bottom line: The unassuming Sony e-reader line features three versions, but only one - The "Daily Edition" - should concern magazine publishers. The Daily Edition is customized for periodicals and includes WiFi for on-the-go downloads.

Sony hasn't sold as many devices as Amazon, but the electronics giant knows how to make consumer gadgets and is beginning to get aggressive in courting publishers. 

Future Players

Apple Tablet

Apple is said to be shopping around its new 10.1-inch tablet touchscreen (right: see a fan's depiction) computer to large publishers in preparation for a Spring launch. The company is remaining close-lipped about the device, but rumors are swirling about the device using the iPhone operating system and being able to run iPhone applications.

JooJoo / Crunchpad

While it may be famous for the legal troubles surrounding the device, this Internet tablet computer eschews on-board storage and is strictly meant to be an for Web browsing. Originally, the device was to cost under $500, though the recent trouble have put the specifics in doubt.

A list of newspaper tablets

Several concept videos of e-reader have been making the rounds. Baekdal.com has compiled all of them.