Amazon.com has sold all existing stocks of the $189 version of its Kindle e-reader.
The company has yet to announce when it will receive new stock.
In a notice posted on its website, the company said: “We'll e-mail you with an estimated delivery date as soon as we have more information.”
The fact that Amazon's Kindle is out of stock suggests that the company is maintaining its market position in the face of increasing competition from Apple, Barnes & Noble and others.
Apple has sold 3.27 million iPads since launch, but it appears the tablet computer has yet to affect the Kindle's popularity.
Experts had expected sales of the Kindle e-book reader to dwindle after Apple reported selling more than a million iPads within 28 days of its launch, along with 1.5 million e-books from its iBookstore.
Tech mag PC World reports that in a conference call with investors last week, Amazon CFO Thomas Szkutak, said: “We're seeing very, very strong [Kindle] device growth and we're seeing very, very strong content growth.”