Amazon.com is sold out of the US$189 version of its popular Kindle e-readers, and the company did not say when new stock will come in.
The company posted a note on its website that not only says that the Kindle is temporarily out-of-stock, but that it will have to "e-mail you with an estimated delivery date as soon as we have more information."
Amazon did not immediately respond to e-mails or phone calls about the situation.
The fact the Kindle has sold out shows Amazon is facing down the threat from Apple's iPad, which has sold millions of units since it was launched last May. A number of industry watchers had forecast that Amazon would take a hit from the iPad after Apple announced it had sold 1 million of the devices just 28 days after release, and over 1.5 million e-books downloaded from the new iBookstore.
Soon after, Amazon dropped the price of the Kindle to $189 from $259.
Last week, Amazon said it had "reached a tipping point with the new price of Kindle." The growth rate of Kindle device unit sales had tripled since the price cut.
"We're seeing very, very strong [Kindle] device growth and we're seeing very, very strong content growth," said Thomas Szkutak, chief financial officer of Amazon, during a conference call with investors last week.
Apple last week said it had already sold 3.27 million iPads. Amazon has not said how many Kindle devices have been sold so far.