Website Magazine has been busy putting the finishing touches on its iPad app (request advance notification of the official release here), but don’t think for a moment that we haven’t thought about placing content on other tablet and reading devices as well.

That choice was confirmed as a good one this morning when we discovered that the new generation Kindle is the best selling product on Amazon now, and more of the devices were sold in the first four week after launch than any other Kindle launch.

“Kindle is the best-selling product on Amazon.com for two years running and our new generation Kindles are continuing that momentum,” said Steven Kessel, senior vice president, Amazon Kindle. “Readers are excited about all that the new Kindle has to offer—50 percent better contrast, 20 percent faster page turns, 15 percent lighter, up to one month of battery life—and a new price of only $139.”

If you are a content publisher should you put your content on the Kindle? The many nice features of the Kindle aside (better screen contrast than previous versions, lighter weight, faster page turns, one-month of battery life, double the storage, and built in wi-fi) are overshadowed the accessibility in price. The new Kindle retails at $139 (those with 3G retail at $189) which should make it a medium of note for content publishers.