Amazon.com is once again claiming a sales milestone for the Kindle without releasing numbers that would place the e-reader's success in context. In the latest achievement, Amazon.com says the latest Kindle is the bestselling product in the 15-years the online retailer has been open for business.

While keeping actual sales numbers to itself, Amazon.com said Monday that sales of the third-generation Kindle eclipsed those of the previous champ, "Harry Potter and the Deathly Hallows," book seven of the popular series.

Amazon.com claimed that "many" people buying Kindles also own a tablet computer, which the retailer says they are using for games, movies, and Web browsing while the Kindle is favored for reading. Of course, "many" is too vague a term to be an indication whether Kindle sales are being negatively affected by tablets, or more specifically, the Apple iPad, which accounts for more than 95% of tablets sold today.

Amazon said in a statement that iPad owners are also buying Kindles, despite the fact that the Apple device can perform the same book-reading functioning, because the Kindle is cheap, $139 for the Wi-Fi-only version. In addition, the device weighs less, has a battery life of a month, and an E Ink digital paper display that can be read in sunlight and doesn't cause eyestrain like LCD screens used in the iPad and computer monitors.

While Amazon.com is trying to give the impression that the iPad is having little impact on the Kindle, research indicates the opposite. From Aug. 1 to Nov. 8, the Kindle's share of the e-reader market fell 15 percentage points to 47%, while the iPad's share rose 16 percentage points to 32%, according to the ChangeWave Research. The rest of the market includes the Sony Reader at 5% and the Barnes & Noble Nook with 4%.

Full story: InformationWeek