Amazon.com, Inc. (NASDAQ:AMZN) began shipping its latest Kindle model, the Kindle Paperwhite, last Monday. Anybody who stalled on purchasing the new e-reader will be disappointed to find it has already sold out. The news emboldens investors who may have worried about the Wal-Mart Stores Inc. (NYSE:WMT) decision to stop selling the devices.

The company’s website is currently showing an expected shipping time of 4 to 6 weeks for the product. The device has been a critical hit, improving on the perceived problems associated with last year’s Kindle Touch, and even drawing in customers that already own a Kindle model.

Amazon Kindle paperwhite

The Kindle Paperwhite is the first Kindle to include a back light. That innovation comes in response to a back light version of arch rival Barnes & Noble Inc. (NYSE:BKS) Nook e-reader.

That device, released earlier this year under the agile name Nook Simple Touch With Glowlight, was lowered in price last week to match the Kindle Paperwhite’s $120 starting label. The e-reader had previous sold for $140.

Amazon.com Inc. (NASDAQ:AMZN) and Barnes & Noble, Inc. (NYSE:BKS) have been, for some years now, waging a war on the feature lists of their e-reader models. As one e-reader gains an edge, the other takes it and improves upon it while at the same time adding something different.

According to reviews of the latest device from Amazon.com, Inc. (NASDAQ:AMZN) The Kindle Paperwhite has a back light superior to that included in Barnes and Noble’s competing device, and improves greatly on the efficacy of the touch screen on the e-reader.

Amazon.com Inc. (NASDAQ:AMZN) will be pleased with the performance of the device. The company is one of the most embattled in the modern tech landscape, competing with most of the other players in the market. Barnes & Noble, Inc. (NYSE:BKS) and Wal-Mart Stores, Inc. (NYSE:WMT)

As a Google Inc (NASDAQ:GOOG) tablet, the Kindle Fire competes directly with Apple Inc. (NASDAQ:AAPL) and Microsoft Corporation (NASDAQ:MSFT), as well as the other Android manufacturers. The company also wages war with almost every single online marketplace.

Competing on so many fronts can make it difficult to see the whole picture at Amazon.com, Inc. (NASDAQ:AMZN), and the Kindle Paperwhite is almost certainly just a small part of that. The company’s new Kindle Fire model has seen an increase in size and, therefore, a shift to more direct competition with premium tablets.

Kindle lovers will have to wait to get their hands on the Kindle Paperwhite. Investors will have to wait to get their hands on the company’s third quarter results. those are expected toward the end of this month.

The Amazon.com, Inc. (NASDAQ:AMZN) hardware business is one of the most interesting in the tech world right now. The company’s surprise showing last Christmas might be repeated if the company manages to sell enough of its Kindle Fire HD tablets, and of course its new e-readers.

The firm needs to figure out how to tighten its supply model so problems like this, just days after release, happen less often.