Many iPad users aren't in an exclusive relationship with their device. According to a JP Morgan study, 40 percent of iPad owners also have a Kindle.

Tech Crunch reported that the study shows that the iPad is not a Kindle killer. In fact, 23 percent of iPad users said that they plan to buy a Kindle in the next year.

The iPad and the Kindle are obviously very different devices. Strictly an e-reader, at $139, the Kindle won't put a huge dent in buyers' wallets. Furthermore, the third-generation Wi-Fi version of the device has been Amazon's best selling product ever.

When Amazon made this announcement about a week ago, it also acknowledged that many people that buy Kindles also own a full-color tablet (such as the iPad), which they use for games, movies, and browsing the Web. This leaves e-reading to the Kindle.

But Amazon is notoriously tight-lipped about the number of Kindles it has sold. A recent report from Bloomberg projected that Amazon would sell eight million Kindles in 2010. The only details from Amazon itself came from a Dec. 13 Facebook update in which the company said that it had sold "millions" of the device in the first 73 days of the fourth quarter.

As far as the tablet market goes, the iPad is king. The device debuted in April for $499, and in the third quarter of 2010, Apple sold 4.19 million iPads.

Less than a year after the popular device hit the market, the rumor mill is already churning out reports of a second-generation iPad. Reports have said that the next iPad will include such features as a dual-facing camera for video chatting, a USB port, and retina display.

The "iPad 2" analysts have predicted that Apple will ship roughly 40 million units of the device, far more than the first iPad's estimated 12.9 million for 2010, according to iSuppli.

Despite strong sales reports for both the Kindle and the iPad, it seems the devices are able to co-exist for the time being. Bottom line? The iPad has not rendered the Kindle obsolete as it was predicted to do.